Question

1+2 sinB*cosB/(sinB+cosB)^2

Answer 1

1+2SinBCosB = Sin²B+Cos²B+2SinB·CosB = (SinB+CosB)²  = 1
(SinB+CosB)²       (SinB+CosB)²                     (SinB+CosB)²