A function `f` satisfies the condition `f(x)=f^(prime)(x)+f''(x)+f'''(x)....`, where `f(x)` is an indefinitely differentiable function and dash denotes the order of derivatives. If `f(0)=1` ,then `f(x)` is
(a)`e^(x/2)` (b) `e^x` (c) `e^(2x)` (d) `e^(4x)`

Options

A. `e^(x//2)`
B. `e^(x)`
C. `e^(2x)`
D. `e^(4x)`

Explanation

`"Given "f=f'+f''+f'''+...oo`
`"or "f'=f''+f'''+f'''+...oo`
`"or "f-f'=f'`
`"or "f=2f'`
`"Hence, "(f')/(f)=1//2 or int(f')/(f)dx=int(1)/(2)dx`
`"or "logf(x)=x//2+c`
`"or "f(x)=e^(x//2+c)`
`"Also, "f(0)=1 or c = 0 or f(x) =e^(x//2)`