Question

интеграл от $\pi$/4 до $\pi$/2 1/sin^2x dx

Answer 1

интеграл (1/sin²x dx)  = (-ctqx) | a =/4,b=π/2   =  -(ctqb -ctqa) =   -(ctqπ/2 -ctqπ/4) = -(0 -1) =1