How about using the fact that ?
I have the two equations:
1) x + y = qsin(theta)
2) z = rcos(theta)
The question is eliminate theta and solve for q in terms of x, y, z, and r.
I'm not sure what eliminating theta means, but I have:
arcsin((x+y)/q) = theta
and I substituted that into my top equation. I have no clue on what I should do now.
Also,I don't understand how I can solve for q in terms of z and r when q isn't in the equation with z and r.