Prove the following
1.(1−sin2A)sec2A=1
2.sec4θ−sec2θ=tan4θ+tan2
3.(secθ−tanθ)2=1−sinθ1+sinθ
4.tanθ+secθ−1tanθ−secθ+=1+sinθcosθ
(i) cosecθ+cotθcosecθ−cotθ=(cosecθ+cotθ)2=1+2cot2θ+2cosecθcotθ
(ii) secθ+tanθsecθ−tanθ=(secθ+tanθ)2=1+2tan2θ+2secθtanθ