`If cos theta = n cos ( theta + 2 phi) "show that"(n+1) tan ( theta + phi)= (n-1) cot phi`

If sin theta = k sin (theta + phi),"show that", tan(theta + phi) = (sin phi)/(cos phi -k).

If 2 tan theta = cot phi, "show that" cos(theta - phi) = 3 cos ( theta + phi).

If sin theta=k sin(theta+phi), show that tan(theta+phi)=(sin phi)/(cos phi-k)

If cos theta = ( cos phi -e)/( 1- e cos phi ) , show that tan ""(theta)/( 2) = +- sqrt((1+e)/( 1-e)) tan ""(phi)/(2)

If " "a cos phi = b cos theta," show that " a tan theta + b tan phi = (a+b) tan ((theta + phi)/2)

If cos(theta+phi)=m cos(theta-phi) then tan theta is equal to

If cos theta = (cos phi-e)/(1-e cos phi) , show that : tan frac (theta)(2)= +- sqrt((1+e)/(1-e)) tan frac (phi)(2) .

If tan^2 theta=2 tan^2 phi+1 , show that cos 2 theta+ sin^2 phi=0 .

If cos theta=(2 cos phi-1)/(2-cos phi) , then tan (theta)/(2)=