Find the value of theta:

Question

-810Cos(theta) + 135 + 2430 Sin(theta)Cos(theta) = 0

Can someone please show me how to simplify it to find the value of theta? Thanks!

Answer 1

it is easy to see That theta is PI/2 is one solution, and 3PI/2 is a second solution. Whenever CosTheta is zero...

There may be a second solution, it is not "easy" to find it except by graphing.
graph y=-810Cos(theta) + 135 + 2430 Sin(theta)Cos(theta)
and the solutions if any will be when y is zero