Sin a cos a(tan a+cot a)

Answer 1

do you want to simplify?
sinacosa(sina/cosa+cosa/sina)
sinacosa[(sina)^2+(cosa)^2]/sinacosa
(sina)^2+(cosa)^2.........

Answer 2

sinacosa(sina/cosa + cosa/sin)
= sin^2 a + cos^2 a
= 1