1)

If   f(x)cosxdx=12(f(x))2+C  and f(0)=0 then f'(0)=


A) 1

B) -1

C) 0

D) 2

Answer:

Option A

Explanation:

We have,

f(x)cosxdx=12(f(x))2+C

On differentiating  w.r.t 'x' , we get

   f(x)cosx=12×2f(x).f(x)

     f(x)cosx=f(x).f(x)

   f(x)=cosx

   f(0)=cos0

  f(0)=1