If A, B and C are the angles of a ΔABC, prove that tan(C+A2)=cotB2.
If A, B and C are the angles of a ΔABC then the sum of angles is 180°
A+B+C=π
A+C=π−B
L.H.S=tan(C+A2)=tan(π−B2)
=tan(π2−B2)
=tan(90−B2)
=cotB2=R.H.S