vikas askiitian expert
Last Activity: 14 Years ago
I = e2x(1/x -1/2x2 )dx lim 1 to 2
put 2x =t
differentiate wrt t
dx = dt/2
now integral becomes
I= et (2/t -2/t2 ) /2 dt lim 2 to 4
I= et (1/t -1/t2 )dt lim 2 to 4
ex {f(x) + f1(x)} dx = ex f(x) ( this is identity )
so by using this we get
I=(et /t ) lim 2 to 4
I= (e4 -2e2 )/4 ans