#### Passage II (Q. Nos. 91 to 94)
Let f be a function that is differentiable everywhere and that has the following properties :
- f(x)>0
- f′(0)=−1
- f(−x)=f(x)1 and f(x+h)=f(x)⋅f(h)
A standard result is ∫f(x)f′(x)dx=log∣f(x)∣+C .
If h(x)=f′(x) , then h(x) is given by
a. −f(x)
b. f(x)1
c. f(x)
d. ef(x)