1secA+tanA=?
secA+tanA
secA-tanA
1
sec2A
1secA+tanA=1secA+tanA×secA-tanAsecA-tanA
=secA-tanAsec2A−tan2A
= secA-tanA [∵sec2A−tan2A=1]
1+tanA*tanA/1+cotA*cotA=1-tanA/1-cotA
Prove it