`tan theta=tan alpha`
then what about theta and alpha?

Show that the lines (1-cos theta tan alpha) y^2 -(2cos theta+sin ^2 theta tan alpha )xy +cos theta (cos theta+tan alpha )x^2=0 include an angle alpha between them .

If sin (theta + alpha ) = cos ( theta + alpha), prove that tan theta =(1- tan alpha )/(1 + tan alpha )

If cos theta=(cos alpha cos beta)/(1-sin alpha sin beta), prove that one value of (tan) theta/2=(tan alpha/2-tan beta/2)/(1-t a n alpha/2 tan beta/2).

General solution of tan theta+tan 4 theta+tan 7 theta=tan theta tan 4 theta tan 7 theta is

If sin alpha = lamda sin (theta - alpha ) then prove that tan (alpha - (theta)/(2)) = (lamda -1)/( lamda +1) tan ""(theta)/(2).

Prove that the general solution of tan"theta"=tan"alpha" is given by : theta=npi+alpha,n in Zdot

If msintheta=nsin(theta+2alpha) , then prove that tan(theta+alpha)cotalpha=(m+n)/(m-n) .

If cos theta=(cos alpha cos beta)/(1-sin alpha sin beta), prove that one value of tan (theta/2)=(tan (alpha/2)-tan (beta/2))/(1-tan (alpha/2) tan (beta/2)).

If sin theta = n sin ( theta + 2 alpha ) , show that ( n -1) tan (theta + alpha ) + (n + 1) tan alpha = 0 .

If tan beta=cos theta tan alpha , then prove that tan^(2)""(theta)/(2)=(sin(alpha-beta))/(sin(alpha+beta)) .