`sin theta sin (theta +2phi) - sin phi sin (phi +2 theta) =sin (theta +phi)`

If the distance between two points (a cos theta,a sin theta) and (a cos phi,a sin phi) is 2a then theta is

2sin(theta-phi)=sin(theta+phi)=1

" If "|{:(sin theta cos phi,,sin theta sin phi,,cos theta),(cos theta cos phi,, cos theta sin phi,,-sin theta),(-sin theta sin phi,,sin theta cos phi,,theta):}| then

" If "|{:(sin theta cos phi,,sin theta sin phi,,cos theta),(cos theta cos phi,, cos theta sin phi,,-sin theta),(-sin theta sin phi,,sin theta cos phi,,theta):}| then

" If "|{:(sin theta cos phi,,sin theta sin phi,,cos theta),(cos theta cos phi,, cos theta sin phi,,-sin theta),(-sin theta sin phi,,sin theta cos phi,,theta):}| then

(sin ( theta -phi))/(sin theta sin phi) = cot phi - cot theta.

(sin (theta + phi))/( sin theta cos phi) = cot theta tan phi +1.

cos 2 (theta+ phi) +4 cos (theta + phi ) sin theta sin phi + 2 sin ^(2) phi=

cos 2 (theta+ phi) +4 cos (theta + phi ) sin theta sin phi + 2 sin ^(2) phi=