Prove that 
.
Consider L.H.S. = 
Multiply numerator and denominator by (1 + sin θ):
= 
= 
= 
= 
= [(1/cos θ) + (sin θ/cos θ)]2
= (sec θ + tan θ)2
= R.H.S.
Hence, proved.
16
Prove that .
Consider L.H.S. =
Multiply numerator and denominator by (1 + sin θ):
=
=
=
=
= [(1/cos θ) + (sin θ/cos θ)]2
= (sec θ + tan θ)2
= R.H.S.
Hence, proved.