Sign in
12thPass logo
New chatPYQ LibraryDoubtsRank report
Sign in to see Recents

Your guest activity stays on this device

Sign in to save progress →
Sign in

Differentiation question

2024 · 6 Apr · Shift 2 · Q46
Guest · filters and generic practice availableBrowsing as a guest · PYQ filters and generic practice are available. Sign in only for personalised features and saved progress.
  1. PYQ Library
  2. /JEE Main
  3. /Mathematics
  4. /Differentiation
  5. /2024 · 6 Apr · Shift 2 · Q46

Differentiation question

2024 · 6 Apr · Shift 2 · Q46

JEE MainMathematicsDifferentiationMCQ+4 / −1
Suppose for a differentiable function h,h(0)=0,h(1)=1h, h(0)=0, h(1)=1h,h(0)=0,h(1)=1 and h′(0)=h′(1)=2h^{\prime}(0)=h^{\prime}(1)=2h′(0)=h′(1)=2. If g(x)=h(ex)eh(x)g(x)=h\left(\mathrm{e}^x\right) \mathrm{e}^{h(x)}g(x)=h(ex)eh(x), then g′(0)g^{\prime}(0)g′(0) is equal to:
  1. A
    4
  2. B
    5
  3. C
    3
  4. D
    8
View written solutionFree

Correct answer: A

  1. We are given g(x)=h(ex) eh(x)g(x)=h(e^x)\,e^{h(x)}g(x)=h(ex)eh(x) with h(0)=0,h(1)=1,h′(0)=2,h′(1)=2.h(0)=0,\\ h(1)=1,\\ h'(0)=2,\\ h'(1)=2.h(0)=0,h(1)=1,h′(0)=2,h′(1)=2.

  2. We need to find g′(0)g'(0)g′(0).

  3. Differentiate g(x)g(x)g(x) using the product rule: g′(x)=ddx(h(ex))⋅eh(x)+h(ex)⋅ddx(eh(x)).g'(x)=\frac{d}{dx}\big(h(e^x)\big)\cdot e^{h(x)}+h(e^x)\cdot \frac{d}{dx}\big(e^{h(x)}\big).g′(x)=dxd​(h(ex))⋅eh(x)+h(ex)⋅dxd​(eh(x)).

  4. Now apply the chain rule to each derivative:

    • For h(ex)h(e^x)h(ex), ddxh(ex)=h′(ex)⋅ex.\frac{d}{dx}h(e^x)=h'(e^x)\cdot e^x.dxd​h(ex)=h′(ex)⋅ex.
    • For eh(x)e^{h(x)}eh(x), ddxeh(x)=eh(x)h′(x).\frac{d}{dx}e^{h(x)}=e^{h(x)}h'(x).dxd​eh(x)=eh(x)h′(x).

    So, g′(x)=h′(ex)ex eh(x)+h(ex)eh(x)h′(x).g'(x)=h'(e^x)e^x\,e^{h(x)}+h(e^x)e^{h(x)}h'(x).g′(x)=h′(ex)exeh(x)+h(ex)eh(x)h′(x).

  5. Factor out eh(x)e^{h(x)}eh(x): g′(x)=eh(x)(h′(ex)ex+h(ex)h′(x)).g'(x)=e^{h(x)}\left(h'(e^x)e^x+h(e^x)h'(x)\right).g′(x)=eh(x)(h′(ex)ex+h(ex)h′(x)).

  6. Substitute x=0x=0x=0: g′(0)=eh(0)(h′(e0)e0+h(e0)h′(0)).g'(0)=e^{h(0)}\left(h'(e^0)e^0+h(e^0)h'(0)\right).g′(0)=eh(0)(h′(e0)e0+h(e0)h′(0)).

  7. Use the given values:

    • h(0)=0  ⟹  eh(0)=e0=1h(0)=0 \implies e^{h(0)}=e^0=1h(0)=0⟹eh(0)=e0=1
    • e0=1e^0=1e0=1
    • h′(1)=2h'(1)=2h′(1)=2
    • h(1)=1h(1)=1h(1)=1
    • h′(0)=2h'(0)=2h′(0)=2

    Therefore, g′(0)=1(h′(1)⋅1+h(1)h′(0))=2+1⋅2=4.g'(0)=1\left(h'(1)\cdot 1+h(1)h'(0)\right)=2+1\cdot 2=4.g′(0)=1(h′(1)⋅1+h(1)h′(0))=2+1⋅2=4.

  8. Hence, g′(0)=4.\boxed{g'(0)=4}.g′(0)=4​.

  9. Comparing with the options:

    • A: 444 ✅
    • B: 555
    • C: 333
    • D: 888

So the correct option is A.

PreviousNext

More from Differentiation

  • Let f(x)=ax3+bx2+cx+41 be such that f(1)=40,f′(1)=2 and f′′(1)=4. Then a2+b2+c2 is equal to:2024 · MCQ
  • If loge​y=3sin−1x, then (1−x2)y′′−xy′ at x=21​ is equal to2024 · MCQ
  • Let f(x)=x3+x2f′(1)+xf′′(2)+f′′′(3),x∈R. Then f′(10) is equal to ​.2024 · Numerical
  • Suppose f(x)=(7x2+3x+1)3(2x+2−x)tanxtan−1(x2−x+1)​​. Then the value of f′(0) is equal to2024 · MCQ
  •  Let y=loge​(1+x21−x2​),−1<x<1. Then at x=21​, the value of 225(y′−y′′) is equal to 2024 · MCQ
  • Let g:R→R be a non constant twice differentiable function such that g′(21​)=g′(23​). If a real valued function f is defined as…2024 · MCQ
  • If f(x)=​2cos4x3+2cos4x2cos4x​2sin4x2sin4x3+2sin4x​3+sin22xsin22xsin22x​​, then 51​f′(0)=…2024 · MCQ
  • Let f:R−{0}→R be a function satisfying f(yx​)=f(y)f(x)​ for all x,y,f(y)eq0. If f′(1)=2024, then2024 · MCQ