$\frac{d^2}{dx^2}(2\cos x \cos 3x) = $

  • A
    $2^2(\cos 2x + 2^2\cos 4x)$
  • B
    $2^2(\cos 2x - 2^2\cos 4x)$
  • C
    $2^2(-\cos 2x + 2^2\cos 4x)$
  • D
    $-2^2(\cos 2x + 2^2\cos 4x)$

Explore More

Similar Questions

જો $y = \frac{\sinh^{-1} x}{\sqrt{1+x^2}}$ હોય,તો $(1+x^2) y_2 + 3xy_1 + y = $

જો $y = \sin^{-1} x$ હોય,તો $(1 - x^2) y_2 - x y_1 = $

જો $x = \sin y$ હોય,તો $\frac{d^2 y}{dx^2} = . . . . . .$,$(0 < x < 1)$ શોધો.

જો $f(x) = \sin x + \cos x$ હોય, તો $f\left(\frac{\pi}{4}\right) f^{(iv)}\left(\frac{\pi}{4}\right)$ ની કિંમત શોધો.

જો $y=A \cos n x+B \sin n x$ હોય,તો $y_2+n^2 y$ ની કિંમત કેટલી થાય?

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo