∫0π(sin⁡t)a-1⁢ⅇⅈ⁢b⁢t⁢ⅆ⁡t=π2a-1⁢ⅇⅈ⁢π⁢b/2a⁢B⁡(12⁢(a+b+1),12⁢(a-b+1)),