JEE Main2004MathematicsDefinite IntegrationActual
If f(x)= e^x 1+e^x , l₁= _ f(-a) ^ f(a) x g x(1-x) d x and I₂= _ f(-a) ^ f(a) g x(1-x) d x then the value of l₂ l₁ is
Options
- A2
- B-3
- C-1
- D1
Correct answer
A. 2
Step-by-step solution
f(-a)+f(a)=1I₁= _ f(-a) ^ f(a) x g x(1-x) d x= _ f(-a) ^ f(a) (1-x) g x(1-x) d x ( _a^b f(x) d x= _a^b f(a+b-x) d x )2 I₁= _ f(-a) ^ f(a) g x(1-x) d x=I₂ I₂ / I₁=2 .