[" 13.If "tan^(2)alpha+2tan alpha.tan2 beta=tan^(2)beta+2tan beta.tan2 alpha," then prove that each side is equal to "1" or "],[tan alpha=+-tan beta.]

tan^(If)alpha+2tan alpha*tan2 beta=tan^(2)beta+2tan beta*tan2 alpha

If tan^(2) alpha+ 2tan alpha tan 2 beta= tan^(2) beta+ 2 tan beta tan 2 alpha, show that tan beta=+- tan alpha .

If 2tan alpha=3tan beta then tan(alpha-beta)=

(1+ tan alpha tan beta)^(2) + (tan beta - tan beta)^(2)=

tan^2 alpha+2tan alpha.tan2beta=tan^2 beta+2tan beta.tan2 alpha, if (A) tan^2 alpha+2tan alpha.tan2beta=0 (B) tan alpha+tan beta=0 (C) tan^2 beta+2tanbeta,tan2 alpha=1 (D) tan alpha=tan beta

(1+tan alpha tan beta)^(2)+(tan alpha-tan beta)^(2)=

if 2tan beta+cot beta=tan alpha then prove that cot beta=2tan(alpha-beta)

(1+tan alpha tan beta)^(2) + (tan alpha -tan beta)^(2) =

Prove that (tan alpha+tan beta)/(cot alpha+cot beta)=tan alpha tan beta