tan(theta+135^(@))tan(theta-135^(@))=

tan 135^@

Prove the following identity: quad tan theta tan(theta+60^(@))+tan theta tan(theta-60^(@))+tan(theta+60^(@))tan(theta-60^(@))=

(tan(theta+varphi)+tan(theta-varphi))/(1-tan(theta+varphi)tan(theta-varphi))=tan2 theta

Prove any of the following: tan (45^@+theta)tan (135^@+theta)=-1

prove that (sec theta-tan theta-1)/(sec theta+tan theta-1)=tan theta-sec theta

tan4 theta=4tan theta(1-tan^(2)theta)/(1-6tan^(2)theta+tan^(4)theta)

Prove that: tan4 theta=(4tan theta(1-tan^(2)theta))/(1-tan^(2)theta+tan^(4)theta)

Prove that (tan^(2)2theta-tan^(2)theta)/(1-tan^(2)2thetatan^(2)theta)=tan 3 theta tan theta .

Prove that (tan^(2)2theta-tan^(2)theta)/(1-tan^(2)2thetatan^(2)theta)=tan 3 theta tan theta .