Question

Tan a1 =cot a2 then find cos(a1-a2)/cos (a1+ a2)

Answer 1

$tana_{1} = cota_{2}\\tana_{1} = \frac{1}{tana_{2} }\\ tana_{1} tana_{2} =1  --> Eq.1$

$\frac{cos(a_{1}-a_{2})} {cos(a_{1}+a_{2})}= \frac{cos(a_{1})cos(a_{2})+sin(a_{1})sin(a_{2})}{cos(a_{1})cos(a_{2})-sin(a_{1})sin(a_{2})}\\ dividing by cosa_{1} cosa_{2}\\ \frac{1+tan(a_{1})tan(a_{2})}{1-tan(a_{1})tan(a_{2})}=1/0=\infty$