Explanation

∫₀ ^(π/2)〖sin⁡xdx〗 = −cos(π/2) − (−cos0) = 0 + 1 = 1

∫₀ ^(π/2)〖sin⁡xdx〗 = −cos(π/2) − (−cos0) = 0 + 1 = 1