Differentiation Question 366
Question: $ \frac{d^{20}y}{dx^{20}}(2\cos x\cos 3x) $ =
[EAMCET 1994]
Options:
A) $ 2^{20}(\cos 2x-2^{20}\cos 4x) $
B) $ 2^{20}(\cos 2x+2^{20}\cos 4x) $
C) $ 2^{20}(\sin 2x+2^{20}\sin 4x) $
D) $ 2^{20}(\sin 2x-2^{20}\sin 4x) $
Show Answer
Answer:
Correct Answer: B
Solution:
$ y=\cos 4x+\cos 2x\Rightarrow \frac{d^{20}y}{dx^{20}}=4^{20}\cos 4x+2^{20}\cos 2x $ .
BETA
