Ko‘rsatkichli tengsizliklar foizli o‘sish yoki kamayishda “qachondan boshlab?”, “qancha vaqt ichida?”, “qaysi qiymatlardan katta/kichik?” kabi savollarga javob beradi. Ular eksponensial funksiya grafigi, monotonlik, interval tahlili va real threshold modellarini birlashtiradi.
Noma’lum o‘zgaruvchi kamida bir daraja ko‘rsatkichida qatnashadigan tengsizlik.
x exponent ichida va <,>,≤,≥ belgilaridan biri bor.
Misol: 2^x>16.
Bu emas: x^2>16 — polynomial inequality.
💡 Yechim odatda interval yoki intervallar birlashmasi.
f(x)=a^x, a>1 bo‘lsa x ortishi bilan f(x) qat’iy ortadi.
Katta exponent katta output beradi.
Misol: 2^3<2^5.
Bu emas: (1/2)^3<(1/2)^5 noto‘g‘ri.
💡 Base 1 dan katta bo‘lganda inequality direction saqlanadi.
f(x)=a^x, 0<a<1 bo‘lsa x ortishi bilan f(x) qat’iy kamayadi.
Katta exponent kichik output beradi.
Misol: (1/2)^3>(1/2)^5.
Bu emas: 2^3>2^5 noto‘g‘ri.
💡 Base 1 dan kichik bo‘lganda exponent comparison direction almashadi.
Funksiyaning intervalda qat’iy o‘suvchi yoki qat’iy kamayuvchi bo‘lish xossasi.
Input tartibi output tartibini qanday o‘zgartirishini bildiradi.
Misol: 2^x o‘suvchi, (1/2)^x kamayuvchi.
Bu emas: Har function monotonic deb qabul qilish.
💡 Exponential inequality nazariyasining markazi.
a>1 bo‘lsa a^u<a^v aynan u<v bilan ekvivalent.
Belgi exponentlarga o‘zgarmasdan o‘tadi.
Misol: 3^{2x}>3^4 → 2x>4.
Bu emas: Base 1/3 bo‘lsa shu qoidani o‘zgartirmasdan ishlatish.
💡 ≤ va ≥ uchun ham mos.
0<a<1 bo‘lsa a^u<a^v aynan u>v bilan ekvivalent.
Kamayuvchi funksiya input tartibini teskari qiladi.
Misol: (1/2)^x<(1/2)^3 → x>3.
Bu emas: x<3 deb yozish.
💡 Eng ko‘p xato shu yerda.
Tengsizlikning ikki tomonini bir xil musbat a asosning darajalari sifatida yozish.
Masalan 8 va 4 ni 2 asosida yozish.
Misol: 8^x>4^{x+1} → 2^{3x}>2^{2x+2}.
Bu emas: 2^x>7 da 7 ni majburan 2 darajasi sifatida sodda yozish.
💡 Monotonicity gate common base’dan keyin keladi.
< yoki > belgili tengsizlik; boundary point yechimga kirmaydi.
Endpoint open.
Misol: x>2 → (2,∞).
Bu emas: x>2 ni [2,∞) yozish.
💡 Original equality boundaryda bajarilsa ham strict case’da kiritilmaydi.
≤ yoki ≥ belgili tengsizlik; tenglik bajarilgan boundary point kiritiladi.
Endpoint closed, agar expression defined bo‘lsa.
Misol: x≥2 → [2,∞).
Bu emas: Undefined pointni ≥ sabab kiritish.
💡 Domain exclusion har doim ustun.
Yechim to‘plamini ochiq/yopiq qavslar va union bilan yozish usuli.
Infinite solution setni ixcham ko‘rsatadi.
Misol: x≤-1 yoki x>3 → (-∞,-1]∪(3,∞).
Bu emas: ∞ yonida square bracket ishlatish.
💡 ±∞ doim round parenthesis bilan.
Inequality expression nol bo‘ladigan yoki aniqlanmaydigan t/x qiymat; sign intervalini bo‘ladi.
Sign-chart boundary.
Misol: (t-1)(t-4)<0 uchun 1 va 4.
Bu emas: Har arbitrary sonni critical deb olish.
💡 Rational inequalityda denominator zero ham critical.
Critical valuelar orasida expression ishorasini aniqlash usuli.
Factorlar signi interval bo‘yicha kuzatiladi.
Misol: (t-1)(t-4)<0 → 1<t<4.
Bu emas: Faqat rootsni javob qilish.
💡 Substitution inequalitiesda asosiy vosita.
t=a^x>0 bilan exponential inequalityni algebraik inequalityga aylantirish.
a^{2x}=t^2.
Misol: 4^x-5·2^x+4<0 → t^2-5t+4<0.
Bu emas: t ni istalgan real deb olish.
💡 t>0 filter majburiy.
t=a^x uchun t faqat (0,∞) qiymatlarni qabul qiladi.
Negative va zero t intervals x ga qaytmaydi.
Misol: t<0 qismi bekor qilinadi.
Bu emas: t=0 ni x=-∞ deb yechimga kiritish.
💡 Limit value solution emas.
a>0 bo‘lsa har real x uchun a^x>0.
Output hech qachon 0 yoki negative emas.
Misol: 2^x>-5 barcha real x uchun.
Bu emas: 2^x<0 ni yechimli deb olish.
💡 Universal/no-solution casesni tez beradi.
a^{g(x)}=c, c>0 tenglik inequality uchun boundary beradi: g(x)=log_a c.
Thresholdni aniq log formda topadi.
Misol: 2^x>7 boundary x=log_2 7.
Bu emas: c≤0 uchun log olish.
💡 Monotonicity qaysi tomonni olishni belgilaydi.
Positive tomonlarga ln qo‘llash inequality directionni saqlaydi, chunki ln x o‘suvchi.
ln olishning o‘zi belgini o‘zgartirmaydi.
Misol: 2^x>7 → x ln2>ln7.
Bu emas: ln ni negative argumentga qo‘llash.
💡 Keyingi bo‘lish coefficient signiga qaraydi.
0<a<1 bo‘lsa ln a<0; inequalityni ln a ga bo‘lish belgisini almashtiradi.
Decreasing-base rule log algebra’da ham shu tarzda ko‘rinadi.
Misol: (1/2)^x>3 → x ln(1/2)>ln3 → x<ln3/ln(1/2).
Bu emas: Belgi almashmasdan bo‘lish.
💡 Monotonicity va inequality arithmetic mos keladi.
Modeldagi miqdor katta/kichik bo‘lishi talab qilingan chegaraviy qiymat.
“Kamida”, “ko‘pi bilan”, “oshganda”, “pastga tushganda” iboralari threshold inequality beradi.
Misol: A(t)≥10000.
Bu emas: Targetni equation deb doim faqat bir vaqt nuqtasi izlash.
💡 Inequality interval of time beradi.
Original tengsizlikni qanoatlantiradigan barcha real x lar to‘plami.
Bitta son emas, ko‘pincha interval.
Misol: x>3 → (3,∞).
Bu emas: Faqat boundary x=3 ni javob qilish.
💡 Final answer set sifatida talqin qilinadi.
Noma’lum exponentda qatnashsa exponential inequality strategiyalari kerak.
$a^{g(x)}\square c$
Belgilar: <, >, ≤, ≥.
Avval a>0 va a≠1 ekanini tekshiring; keyin a>1 yoki 0<a<1 branchini tanlang.
$a>1\quad\text{yoki}\quad0
Direction qoidasi base branchga bog‘liq.
a>1 bo‘lsa output inequality exponent inequality bilan ayni yo‘nalishda.
0<a<1 bo‘lsa output inequality exponent inequality bilan teskari yo‘nalishda.
$a^uv$
Strict monotonic decrease.
Strict/non-strict farqi odatda bir xil boundary equationdan keladi; farq endpoint inclusionda.
$a^{g(x)}=c$
Expression boundaryda defined bo‘lishi kerak.
Imkon bo‘lsa logarithmdan oldin common base tanlang.
$2^{g(x)}\square2^{h(x)}$
Exact, tez va rounding yo‘q.
a^{u+v}=a^ua^v va (a^u)^v=a^{uv} common base yaratadi.
$(a^u)^v=a^{uv}$
Exponent algebra to‘g‘ri ochiladi.
a^x>0 range sabab RHS signi ba’zi inequalitiesni darhol hal qiladi.
$a^x>0$
a^x>negative — all real; a^x<negative — empty.
Polynomial-in-a^x ko‘rinishda t=a^x>0 tanlanadi.
$t=a^x>0$
a^{kx}=t^k.
Substitutiondan so‘ng roots t-axisni intervalsga bo‘ladi; factor signlar tekshiriladi.
$P(t)\square0$
Only t>0 region relevant.
Numerator zeros va denominator zeros critical values; denominator points hech qachon solutionga kirmaydi.
$\frac{P(t)}{Q(t)}\square0$
Q(t)≠0 and t>0.
a^x increasing bo‘lgani uchun t interval orderi x da saqlanadi.
$a^x>c\Leftrightarrow x>\log_a c$
a>1,c>0.
a^x decreasing bo‘lgani uchun t orderi x da teskari.
$a^x>c\Leftrightarrow x<\log_a c$
0<a<1,c>0.
Ikki threshold orasidagi inequality ikki order conditionni birga talab qiladi.
$L
L,U>0.
a^x positive bo‘lgani uchun product inequalityda uni bo‘lish signni o‘zgartirmaydi.
$a^xP(a^x)\square0$
a^x>0.
Positive quantitiesga ln qo‘llash inequality directionni saqlaydi.
$U U,V>0.
a>1 da ln a>0; 0<a<1 da ln a<0.
$\operatorname{sgn}(\ln a)$
a>0,a≠1.
Boundary decimalga erta aylantirilmaydi.
$x_0=\frac{\ln c}{\ln a}$
c>0.
≤/≥ bo‘lsa boundary original expressionda defined va equality true bo‘lsa kiritiladi.
$(a,b],\ [a,b)$
Domain first.
∞ va -∞ son emas, endpoint sifatida hech qachon square bracket olmaydi.
$(-\infty,c),\ (c,\infty)$
Always open at infinity.
a^{g(x)} va threshold/function grafiklari qaysi x intervalda biri yuqorida ekanini ko‘rsatadi.
$f(x)>g(x)$
Graphical verification exact algebra’ni tekshiradi.
O‘suvchi exponential modelda targetdan yuqori bo‘lish odatda boundary va undan keyingi vaqtlarni beradi.
$A_0b^t\ge M$
b>1.
Kamayuvchi exponential modelda targetdan past bo‘lish odatda boundary va undan keyingi vaqtlarni beradi.
$A_0b^t\le M$
0<b<1.
Representative test point, endpoint equality va domain bilan solution intervalni tasdiqlang.
$interval\to test$
At least one test per interval when sign-chart used.
O‘suvchi exponential tartibni saqlaydi.
Shart: a>1
Xususiy holatlar: >,≤,≥ uchun ham ayni yo‘nalish.
Kamayuvchi exponential tartibni teskarilaydi.
Shart: 0<a<1
Xususiy holatlar: >,≤,≥ uchun ham yo‘nalish almashadi.
Endpoint inclusion saqlanadi.
Shart: a>1
Endpoint inclusion bilan direction teskari.
Shart: 0<a<1
Exponential output positive.
Shart: a>0
Power of a power.
Shart: a>0
Shifted exponentlar factorlashga yordam beradi.
Shart: a>0
Reciprocal exponential.
Shart: a>0
Exponential inequalityni algebraic inequalityga o‘tkazadi.
Shart: a>0, a≠1
Quadratic pattern.
Shart: t=a^x
Positive factor inequality direction va signni o‘zgartirmaydi.
Shart: a>0
ln strict increasing.
Shart: U>0,V>0
Increasing base threshold direction saqlanadi.
Shart: a>1,c>0
Decreasing base threshold direction teskari.
Shart: 0<a<1,c>0
Exact logarithmic boundary.
Shart: a>0, a≠1, c>0
Threshold x interval right ray.
Shart: a>1,c>0
Threshold x interval left ray.
Shart: 0<a<1,c>0
Upward quadratic negative roots orasida.
Shart: r_1<r_2, leading coefficient>0
Upward quadratic positive outside.
Shart: r_1<r_2, leading coefficient>0
Growth targetga yetilgan vaqtlar.
Shart: A_0,M>0,b>1
Xususiy holatlar: Boundary T=ln(M/A0)/ln b.
Decay target ostiga tushgan vaqtlar.
Shart: A_0,M>0,0<b<1
Xususiy holatlar: Boundary T=ln(M/A0)/ln b.
Continuous growth threshold.
Shart: A_0,M>0,k>0
Xususiy holatlar: t≥ln(M/A0)/k when M>A0.
Continuous decay threshold.
Shart: A_0,M>0,k<0
Xususiy holatlar: Dividing by k<0 reverses direction.
Always true wherever exponent expression real.
Shart: a>0
No real solution.
Shart: a>0
Symbol controls endpoint inclusion after domain check.
Shart: expression defined at boundary
a>1 uchun a^u<a^v bo‘lsa va faqat shunda u<v; shu ekvivalentlik ≤,>,≥ uchun ham mos yo‘nalishda bajariladi.
Strict increasing function input tartibini outputda aynan saqlaydi.
Berilgan: a>1 va real u,v.
Isbotlash kerak: a^u<a^v iff u<v.
O‘suvchi asos order theorem isbotlandi. ∎
0<a<1 uchun a^u<a^v bo‘lsa va faqat shunda u>v; barcha inequality belgilarida yo‘nalish teskari bo‘ladi.
Strict decreasing function input tartibini outputda teskarilaydi.
Berilgan: 0<a<1 va real u,v.
Isbotlash kerak: a^u<a^v iff u>v.
Kamayuvchi asos order theorem isbotlandi. ∎
U,V>0 uchun U<V bo‘lsa va faqat shunda ln U<ln V.
ln x positive domain’da strict increasing.
Berilgan: U,V>0.
Isbotlash kerak: ln tartibni saqlashini ko‘rsatish.
Natural log order-preserving property isbotlandi. ∎
t=a^x almashtirish exponential polynomial/rational inequalityni t>0 sohada algebraik inequalityga teng kuchli aylantiradi.
a^x ning range’i (0,∞) va mapping one-to-one.
Berilgan: t=a^x, a>0,a≠1.
Isbotlash kerak: t-space va x-space solution mapping teng kuchli ekanini ko‘rsatish.
Positive substitution equivalence isbotlandi. ∎
a>0 bo‘lsa har real x uchun a^x>0; shu sabab a^{g(x)}>0 barcha real-domain x lar uchun true, a^{g(x)}≤0 esa yechimsiz.
Exponential graph x-axisni kesmaydi.
Berilgan: a>0 va g(x) real.
Isbotlash kerak: Eksponensial output positive ekanini va zero-threshold consequencesni ko‘rsatish.
Eksponensial positivity va zero-threshold consequences isbotlandi. ∎
💡 Maslahat: 8=2^3 va base 2>1.
✅ Javob: $x>3$
Nega bu usul ishlaydi: O‘suvchi eksponensial funksiya orderni saqlaydi.
⚠️ Base 2>1 ekanini explicit tekshiring.
💡 Maslahat: 27=3^3.
✅ Javob: $x\le2$
Nega bu usul ishlaydi: Increasing-base non-strict rule.
⚠️ ≤ endpoint x=2 ni kiritadi.
💡 Maslahat: Ikkalasini 2 asosida yozing.
✅ Javob: $x<2$
Nega bu usul ishlaydi: Common base va increasing order rule.
⚠️ 2x+2>3x dan x>2 emas, x<2 chiqadi.
💡 Maslahat: 9=3^2.
✅ Javob: $x<3$
Nega bu usul ishlaydi: Common base exponent inequalityga tushadi.
⚠️ 2(x-1)=2x-2.
💡 Maslahat: Base 1/2 kamayuvchi.
✅ Javob: $x<3$
Nega bu usul ishlaydi: Decreasing exponential input orderni teskarilaydi.
⚠️ Belgi exponentlarga o‘tganda almashadi.
💡 Maslahat: 1/27=(1/3)^3.
✅ Javob: $x\ge2$
Nega bu usul ishlaydi: Decreasing-base ≤ rule exponentda ≥ ga aylanadi.
⚠️ Endpoint x=2 tenglik beradi va kiritiladi.
💡 Maslahat: 1/4=(1/2)^2.
✅ Javob: $x>2$
Nega bu usul ishlaydi: Common decreasing base yo‘nalishni teskarilaydi.
⚠️ Avval common base, keyin base branch.
💡 Maslahat: 25=(1/5)^{-2}.
✅ Javob: $x>0$
Nega bu usul ishlaydi: 25 ni decreasing common base’da yozish exact yechim beradi.
⚠️ 25=5^2=(1/5)^{-2}.
💡 Maslahat: 1=2^0.
✅ Javob: $x\ge0$
Nega bu usul ishlaydi: Increasing common base.
⚠️ Non-strict endpoint 0 kiradi.
💡 Maslahat: 1=(1/2)^0.
✅ Javob: $x\le0$
Nega bu usul ishlaydi: Decreasing order reversal.
⚠️ ≥ exponentda ≤ ga aylanadi.
💡 Maslahat: Eksponensial output positive.
✅ Javob: $x\in\mathbb R$
Nega bu usul ishlaydi: Positivity shortcut.
⚠️ Logarithm olishga hojat yo‘q.
💡 Maslahat: Range (0,∞).
✅ Javob: Yechim yo‘q.
Nega bu usul ishlaydi: Exponential graph x-axisdan yuqorida.
⚠️ x→-∞ da 0 ga yaqinlashadi, ammo 0 dan kichik bo‘lmaydi.
💡 Maslahat: 3^x doim positive.
✅ Javob: Yechim yo‘q.
Nega bu usul ishlaydi: Positivity range.
⚠️ Zero ham range ichida emas.
💡 Maslahat: Positive base.
✅ Javob: $x\in\mathbb R$
Nega bu usul ishlaydi: Positivity base size’dan qat’i nazar ishlaydi.
⚠️ Kamayuvchi bo‘lish positive range’ni o‘zgartirmaydi.
💡 Maslahat: 4=2^2, 16=2^4.
✅ Javob: $2<x<4$
Nega bu usul ishlaydi: Increasing mapping compound intervalni saqlaydi.
⚠️ Ikkala endpoint strict sabab ochiq.
💡 Maslahat: 1/9=3^{-2}, 27=3^3.
✅ Javob: $-2\le x<3$
Nega bu usul ishlaydi: Increasing base compound orderni saqlaydi.
⚠️ Chap endpoint kiritiladi, o‘ng endpoint strict.
💡 Maslahat: 1/8=(1/2)^3, 4=(1/2)^{-2}.
✅ Javob: $-2\le x<3$
Nega bu usul ishlaydi: Decreasing mapping ikki boundary tartibini teskarilaydi.
⚠️ Compound inequalityni bitta mechanical flip bilan chalkashtirmang; har qismini tekshiring.
💡 Maslahat: t=2^x>0.
✅ Javob: $0<x<2$
Nega bu usul ishlaydi: Upward quadratic roots orasida negative; increasing t-map x intervalni saqlaydi.
⚠️ t>0 domainni yozing.
💡 Maslahat: Oldingi quadraticning outside intervalsini oling.
✅ Javob: $x\le0\;\text{yoki}\;x\ge2$
Nega bu usul ishlaydi: Quadratic sign outside roots nonnegative.
⚠️ t<0 algebraik qism x-space’ga qaytmaydi.
💡 Maslahat: t=3^x>0.
✅ Javob: $0\le x\le2$
Nega bu usul ishlaydi: Quadratic nonpositive roots orasida.
⚠️ Endpoints equality sabab kiritiladi.
💡 Maslahat: t=2^x>0.
✅ Javob: $x<0\;\text{yoki}\;x>1$
Nega bu usul ishlaydi: Upward quadratic positive outside roots.
⚠️ t=0 intervalning endpointi emas; t faqat positive.
💡 Maslahat: t=2^x>0.
✅ Javob: $x<1$
Nega bu usul ishlaydi: Substitution domain algebraik intervalni qisqartiradi.
⚠️ -1<t<0 qismi a^x qiymati bo‘la olmaydi.
💡 Maslahat: Positive common factor ajrating.
✅ Javob: $x>\log_2 3$
Nega bu usul ishlaydi: Positive factor signni o‘zgartirmaydi.
⚠️ 2^x=0 branch yo‘q.
💡 Maslahat: t=3^x>0.
✅ Javob: $x\ge0$
Nega bu usul ishlaydi: t>0 negative branchni olib tashlaydi.
⚠️ t≤-3 ni x solution deb qabul qilmang.
💡 Maslahat: t=2^x>0 va t+1/t≥2 theorem.
✅ Javob: $x\in\mathbb R$
Nega bu usul ishlaydi: Reciprocal-sum theorem universal lower bound beradi.
⚠️ Bu inequalityni faqat x=0 deb javob bermang; x=0 faqat equality point.
💡 Maslahat: t+1/t≥2.
✅ Javob: Yechim yo‘q.
Nega bu usul ishlaydi: Theorem minimum 2 ekanini beradi.
⚠️ Numerical guessingga hojat yo‘q.
💡 Maslahat: t=2^x>0.
✅ Javob: $-1\le x\le1$
Nega bu usul ishlaydi: Quadratic sign-chart va increasing mapping.
⚠️ t ga ko‘paytirish qonuniy, chunki t>0.
💡 Maslahat: Oldingi quadraticning outside intervalsini oling.
✅ Javob: $x<-1\;\text{yoki}\;x>1$
Nega bu usul ishlaydi: Quadratic positive outside roots.
⚠️ Strict endpointlar kiritilmaydi.
💡 Maslahat: t=2^x>0; critical t=1,4.
✅ Javob: $x<0\;\text{yoki}\;x>2$
Nega bu usul ishlaydi: Rational sign chart numerator/denominator critical valuesni ishlatadi.
⚠️ x=2 denominator zero, hech qachon kiritilmaydi.
💡 Maslahat: t-space sign chart.
✅ Javob: $0\le x<2$
Nega bu usul ishlaydi: Endpoint inclusion numerator zero va denominator undefinedni farqlaydi.
⚠️ ≤ bo‘lsa ham denominator-zero endpoint kirmaydi.
💡 Maslahat: 2^x positive factor.
✅ Javob: $x\ge\log_2 3$
Nega bu usul ishlaydi: Positive common factorni bo‘lish directionni saqlaydi.
⚠️ 2^x=0 equality branch mavjud emas.
💡 Maslahat: 3^x>0.
✅ Javob: $x<2$
Nega bu usul ishlaydi: Positive exponential factor signga ta’sir qilmaydi.
⚠️ Product <0 uchun 3^x negative branch izlamang.
💡 Maslahat: Common base yo‘q; ln oling.
✅ Javob: $x>\frac{\ln7}{\ln2}$
Nega bu usul ishlaydi: Natural log increasing, ln2 positive.
⚠️ Approximationni endpointning exact formi o‘rniga erta ishlatmang.
💡 Maslahat: ln olib exponentni tushiring.
✅ Javob: $x\le\frac{1+\ln11/\ln5}{2}$
Nega bu usul ishlaydi: Positive logarithmic coefficient directionni saqlaydi.
⚠️ ≤ endpoint kiritiladi.
💡 Maslahat: ln(1/2)<0.
✅ Javob: $x<\frac{\ln3}{\ln(1/2)}$
Nega bu usul ishlaydi: Decreasing-base rule ln coefficient signi orqali ko‘rinadi.
⚠️ ln olish emas, negative ln(1/2) ga bo‘lish belgini almashtiradi.
💡 Maslahat: ln(1/3)<0.
✅ Javob: $x>\frac{\ln5/\ln(1/3)-1}{2}$
Nega bu usul ishlaydi: Decreasing base inequality directionni reverses.
⚠️ Negative denominator bilan inequality flipni unutmang.
💡 Maslahat: ln e=1.
✅ Javob: $x\ge\ln3$
Nega bu usul ishlaydi: e^x increasing va ln exact boundary beradi.
⚠️ 9 ni e^9 deb qabul qilmang.
💡 Maslahat: ln olib -0.5 ga bo‘lishda belgini almashtiring.
✅ Javob: $x<-2\ln4$
Nega bu usul ishlaydi: Negative linear coefficient inequality directionni reverses.
⚠️ e base increasing bo‘lsa ham exponent equation ichida -0.5 coefficient bor.
💡 Maslahat: 0.01=10^{-2}.
✅ Javob: $x>3$
Nega bu usul ishlaydi: Common base, keyin linear inequality sign rule.
⚠️ -x<-3 dan x<3 emas; -1 ga bo‘lganda flip bo‘ladi.
💡 Maslahat: 0.2=1/5, 25=(1/5)^{-2}.
✅ Javob: $x\ge-2$
Nega bu usul ishlaydi: Decreasing common base flips direction.
⚠️ 25 ni (1/5)^2 deb yozmang.
💡 Maslahat: Boundary oldingi equation: 500·2^{t/3}=4000.
✅ Javob: $t\ge9$
Nega bu usul ishlaydi: Growth model increasing, targetga yetilgach undan yuqorida qoladi.
⚠️ Savol bitta vaqt emas, vaqt intervalini so‘raydi.
💡 Maslahat: 125/1000=1/8=(1/2)^3.
✅ Javob: $t\ge15$
Nega bu usul ishlaydi: Decay modelda vaqt oshishi outputni kamaytiradi.
⚠️ Decreasing base sabab exponent inequality reverses.
💡 Maslahat: Avval 500 ga bo‘ling.
✅ Javob: $t>5\ln2$
Nega bu usul ishlaydi: Continuous growth increasing threshold.
⚠️ Strict > sabab boundary kiritilmaydi.
💡 Maslahat: 20/80=1/4.
✅ Javob: $t>10\ln4$
Nega bu usul ishlaydi: Negative decay coefficient sabab time threshold right rayga aylanadi.
⚠️ Minus coefficient bilan bo‘lishda flipni unutmang.
💡 Maslahat: 1.1^t≥1.5.
✅ Javob: $t\ge\frac{\ln1.5}{\ln1.1}\approx4.254$
Nega bu usul ishlaydi: Growth factor >1, thresholddan keyingi barcha vaqtlar yechim.
Muqobil usul: Diskret butun-davr modelida minimal period 5.
⚠️ Continuous t va integer period interpretationni ajrating.
❌ Bir xil asosga kelgach base’ni tekshirmasdan belgini saqlash.
0<a<1 bo‘lsa exponential funksiya kamayuvchi va exponent comparison yo‘nalishi teskari.
✅ Avval a>1 yoki 0<a<1 ekanini aniqlang.
(1/2)^x>(1/2)^3 → x<3.
❌ 0<a<1 holatda har safar butun tengsizlik belgisini ikki marta almashtirish.
Faqat monotonic mapping yoki negative coefficientga bo‘lish bosqichida bitta mantiqiy reversal bor.
✅ Qadamlarni yozib, qayerda flip bo‘layotganini aniq ko‘rsating.
x ln(1/2)>ln3 → x<ln3/ln(1/2).
❌ 4^x va 8^x ni common base’siz exponentlari bilan to‘g‘ridan solishtirish.
Different bases uchun exponent comparison qoidasi bevosita ishlamaydi.
✅ 4=2^2, 8=2^3 qilib common base yarating.
4^{x+1}>8^x.
❌ Strict inequalityda boundary pointni solutionga kiritish.
< va > equalityni rad etadi.
✅ Strict endpointni round parenthesis bilan yozing.
x>3 → (3,∞).
❌ ≤ yoki ≥ bo‘lsa har qanday boundary pointni avtomatik kiritish.
Boundary expression undefined bo‘lishi mumkin.
✅ Avval domainni tekshiring; denominator-zero point hech qachon kirmaydi.
(2^x-1)/(2^x-4)≤0 da x=2 chiqariladi.
❌ ∞ yonida square bracket ishlatish.
Infinity real endpoint emas.
✅ ±∞ yonida har doim round parenthesis ishlating.
[2,∞), not [2,∞].
❌ a^x<0 uchun logarithm olish.
Positive-base exponential hech qachon negative emas; log negative threshold real emas.
✅ Positivity gate bilan darhol no solution deb xulosa qiling.
2^x<0.
❌ a^x>-5 kabi inequalityni murakkab yechishga urinish.
a^x>0 barcha real x uchun, shuning uchun >-5 universal true.
✅ Range/positivityni avval tekshiring.
2^x>-5 → R.
❌ t=a^x substitutionda t≤0 intervalni saqlab qolish.
t range faqat (0,∞).
✅ Sign-chart solutionni t>0 bilan kesishiring.
t^2-t-2<0 → -1<t<2, lekin final 0<t<2.
❌ a^{2x}=2a^x deb substitution qilish.
a^{2x}=(a^x)^2.
✅ t=a^x bo‘lsa a^{2x}=t^2.
4^x=(2^x)^2.
❌ Quadratic inequalityda faqat rootsni javob qilish.
Inequality roots emas, roots orasidagi yoki tashqarisidagi intervalni so‘raydi.
✅ Factor sign-chart tuzing.
(t-1)(t-4)<0 → 1<t<4.
❌ Rational sign-chartda denominator rootni ≥/≤ sabab kiritish.
Denominator zero nuqtada expression aniqlanmagan.
✅ Denominator roots doim open/excluded.
(t-1)/(t-4)≤0 da t=4 kirmaydi.
❌ ln olish tengsizlik belgisini avtomatik almashtiradi deb o‘ylash.
ln positive domain’da increasing, demak log transform o‘zi directionni saqlaydi.
✅ Flip faqat keyin negative coefficientga bo‘lganda bo‘lishi mumkin.
ln U<ln V iff U<V.
❌ 0<a<1 holatda ln a ga bo‘lganda belgini saqlash.
ln a<0.
✅ Negative ln a ga bo‘lganda inequality directionni almashtiring.
(1/2)^x>3.
❌ Approximate boundaryni erta yaxlitlab intervalni shunga qurish.
Rounding exact endpoint yaqinida classification xatosi berishi mumkin.
✅ Exact log boundaryni saqlang, approximationni oxirida yozing.
x>ln7/ln2, keyin ≈2.807.
❌ Compound inequalityda decreasing base uchun endpointlarni mexanik tartibda qoldirish.
Decreasing mapping input/output tartibini teskari qiladi.
✅ Har inequality qismini alohida map qilib keyin kesishiring.
1/8<(1/2)^x≤4 → -2≤x<3.
❌ Positive common exponential factor signni o‘zgartirishi mumkin deb alohida branch ochish.
a^x>0, shuning uchun factor signi doim positive.
✅ Positive factorni bo‘lish directionni saqlaydi.
2^x(2^x-3)≥0 ↔ 2^x-3≥0.
❌ Linear inequalityda negative coefficientga bo‘lganda flipni unutish.
Bu umumiy inequality arifmetik qoidasi.
✅ Negative songa bo‘lsangiz belgini almashtiring.
1-x<-2 → x>3.
❌ Growth threshold savoliga faqat equality vaqtini javob qilish.
“Qachondan boshlab kamida” interval of times so‘raydi.
✅ Boundaryni topib model monotonicity bo‘yicha rayni tanlang.
500·2^{t/3}≥4000 → t≥9.
❌ Real modelda t<0 vaqtlarni algebraik solution sifatida qoldirish.
Context domain ko‘pincha t≥0.
✅ Final solutionni physical/context domain bilan kesishiring.
Population yoki decay time negative bo‘lmaydi.
Ko‘rsatkichli tengsizlik equation kabi faqat boundary sonni beradi.
Inequality solution odatda interval yoki intervallar birlashmasi; boundary faqat intervalni bo‘luvchi nuqta.
Base 1 dan kichik bo‘lsa expression manfiy bo‘ladi.
Yo‘q. 0<a<1 exponential output baribir positive; faqat funksiya kamayuvchi.
0<a<1 da exponent kattalashsa output ham kattalashadi.
Aksincha, output kamayadi; shu sabab order reversal yuz beradi.
Logarifm olish har doim inequality belgisini almashtiradi.
ln increasing; positive argumentsda direction saqlanadi. Flip negative coefficientga bo‘lishda yuz beradi.
t=a^x substitutionda t barcha real sonlarni qabul qiladi.
t faqat positive; zero va negative t x-space’da mavjud emas.
Sign-chart faqat rational inequalities uchun.
Polynomial-in-a^x exponential inequalities ham substitutiondan keyin sign-chart talab qiladi.
Non-strict inequalityda barcha critical points kiritiladi.
Faqat expression defined va equality true bo‘lgan points kiritiladi; denominator zeros chiqariladi.
Exponential inequality har doim bir interval beradi.
Quadratic/rational substitution cases ikki yoki undan ko‘p interval union berishi mumkin.
Growth threshold va decay threshold bir xil direction beradi.
Model monotonicity farq qiladi: growth output time bilan ortadi, decay kamayadi; threshold ray shunga qarab talqin qilinadi.
Decimal endpoint exact javobdan afzal.
Exact logarithmic endpoint rounding xatosisiz boundary beradi; decimal faqat qo‘shimcha approximation.
Investitsiya yoki qarz ma’lum thresholdga qachon yetishi yoki undan oshishini aniqlash.
Populyatsiya minimal/maximal chegaraga qaysi vaqt intervalida tushishini topish.
Qolgan modda miqdori xavfsiz threshold ostiga qachon tushishini aniqlash.
Dori konsentratsiyasining terapevtik intervalda qancha vaqt qolishini exponential inequalities bilan baholash.
Sig‘im yoki signal kuchi threshold ostiga qachon tushishini decay model bilan aniqlash.
Narx yoki indeks ma’lum limitdan oshadigan davrlarni topish.
Eksponensial response funksiyasining ruxsat etilgan operating threshold intervalini aniqlash.
Monotonicity, sign-chart, interval notation va logarithmic boundary kombinatsiyasi algebra testlarida yuqori darajali ko‘nikma.
Monotonicity map base >1, base between 0 and 1, substitution/sign-chart and final interval QA pathsini birlashtiradi.
Cheat sheet: $a>1$: $a^u\square a^v\Leftrightarrow u\square v$; $0<a<1$: exponentlarni solishtirganda belgi almashadi. $a^x>0$. $t=a^x>0$ substitutionda avval t-space inequality, keyin x-space mapping. Common base bo‘lmasa $a^{g(x)}\square c$, c>0 uchun boundary $g(x)=\log_a c$; base kamayuvchi bo‘lsa yo‘nalish teskari. Endpoint inclusion $<$/$>$ da ochiq, $\le$/$\ge$ da tenglik bajarilsa yopiq.
Keyingi mavzular logarifmlarni hisoblash va logarifmik shakl almashtirishdir. Ularda bu yerda ishlatilgan logarithmic boundary va monotonicity g‘oyalari logarifmik tengsizliklar uchun ham asos bo‘ladi.
Oldin bilishingiz kerak: Daraja va uning xossalari, darajali ifodalar, Chiziqli tengsizlik va tengsizliklar sistemasi, Ratsional ko'rsatkichli daraja va uning xossalari, Funksiya, Ko'rsatkichli tenglama
Bog'liq mavzular: Ratsional tengsizliklar
Keyingi mavzular: Logarifmlar: hisoblashga doir masalalar, Logarifmik tengsizliklar