Evaluate `int_(1)^(infty) x/e^(x/2)dx`

Evaluate int_(0)^(infty) e^(-x)x^(3)dx .

The value of int_(0)^(infty)[2e^(-x)] dx (where ,[.] denotes the greatest integer function of x) is equal to S

Evaluate :int_(1)^(e)(log x)/(x)dx

Evaluate : (i) int_(0)^(2)e^(x//2)dx (ii) int_(2)^(4)(x)/((x^(2)+1))dx (iii) int_(0)^(1)cos^(-1)xdx

Evaluate int_(1)^(e) (1)/(x)dx

Evaluate int_(0)^(2)e^(x)dx

" Evaluate "int_(1)^(e)(1)/(x)dx