Question

If 3 cot A=4,then check whether 1-tansquare A/1+tansquare A =cos square A -sin square A

Answer 1

CotA=4/3

TanA=3/4

SinA=3/5

cosA=4/5

L.H.S.=(1-9/16)/(1+9/16)

=(7/16)/(25/16)

=7/25

R.H.S.=16/25-9/25

=7/25

Hence,

L.H.S.=R.H.S.=7/25