Question

Help please! I’m so stuck, trig identities

Answer 1

This is not an identity. Consider
`a=0^\circ`, for which you get

`(\sin0^\circ+\sin(90-0)^\circ+1)/(\sin0^\circ-\sin(90-0)^\circ)=(0+1+1)/(0-1)=-2`

but
`\cot0=\frac1{\tan0}=\frac10` is undefined.