Question

Prove the following identities:1\secA-1+1/secA+1=2 cosecA. CotA

Answer 1

tanA (1- secA) – tanA (1+secA) / 1- sec^2A

= -2tanAsecA / 1- (1 + tan^2A)

= -2tanAsecA / -tan^2A

= 2secA / tanA

= secA * cotA
= 2/ cosA * cosA / sinA
= 2/ sinA
= 2 tanA (1- secA) – tanA (1+secA) / 1- sec^2A

= -2tanAsecA / 1- (1 + tan^2A)

= -2tanAsecA / -tan^2A

= 2secA / tanA

= secA * cotA
= 2/ cosA * cosA / sinA
= 2/ sinA
= 2 cosecA proved