Name: Kevin
Who is asking: Student
Level of the question: All

Question: I am trying to solve for A and B but haven't been able to find a trig identity that will help me.

1.414 = .5cosA + cosB
.5 = .5sinA - sinB

how do I solve this?


Hi Kevin,

If you square the two equations you get

2 = 0.25 cos2 A + cos2 B + cos A cos B
0.25 = 0.25 sin2 A + sin2 B - sin A sin B

Now add the two equations and simplify using the fact that sin2 X + cos2 X = 1.

Do you now see a trig identity that helps?