Ques. 1JEE Main 2025, 22 January (Morning Shift)
Let f(x) be a real differentiable function such that f(0)=1 and f(x+y)=f(x)f'(y)+f'(x)f(y) for all x,y . Then n=1100 ef(n) is equal to :
- 2406
- 5220
- 2525
- 2384
Answer
(3) 2525
Solution
x=y=0: 1=2f'(0) f'(0)= 12
y=0: f(x)= 12f(x)+f'(x) f'(x)= 12f(x) f(x)=ex/2
ef(n)= n2
n=1100 n2= 12 100 1012=2525
Answer: (3)