Most Important Selected Qs for JEE AdvancedMathematicsDefinite Integration
If f(x)= ₁^x t 1+t d t , then
Options
- Af ( 1 x )=- ₁^x t t(1+t) d t
- Bf ( 1 x )= ₁^x t t(1+t) d t
- Cf(x)+f ( 1 x )=0
- Df(x)+f ( 1 x )= 1 2 ( x)^2
Correct answer
D. f(x)+f ( 1 x )= 1 2 ( x)^2
Step-by-step solution
f ( 1 x )= ₁^ 1 / x t (1+t) d t= ₁^x - u 1+u u -1 u^2 d u= ₁^x t t(1+t) d t Now, f(x)+f ( 1 x )= ₁^x t (1+t) (1+ 1 t ) d t= ₁^x t t d t= [ ( t)^2 2 ]₁^x= ( x)^2 2