WBJEE2018MathematicsIndefinite IntegrationActual
If f(x) x x d x= 1 2 (b²-a² ) f(x)+c where c is the constant of integration, then f(x) is equal to
Correct answer
2
Step-by-step solution
We have. f(x) x x d x= 1 2 b²-a² (f(x))+c f(x) x x= 1 .2 b²-a² ) 1 f(x) f'(x) f(x) 2 x= 1 b²-a² f'(x) f(x) 2 x= 1 b²-a² f(x) (f(x))² 2 x d x= 1 b²-a² f(x) (f(x))² d x - 2 x 2 = 1 b²-a² ( -1 f(x) ) 2 x (b²-a² ) 2 = 1 f(x) f(x)= 2 (b²-a² ) 2 x