In two or more complete sentences, explain why cos(30°) + cos(60°) ≠ cos(90°)

Question

asked May 17, 2020 210k views

1 Answer

GeekySelene · Answer 1 · 2020-05-20T16:52:35+0000

By using the 30-60-90 right triangle, or the unit circle, you can find (without a calculator) that

$\cos30^o=√(3) /2$

$\cos60^o=1/2$

$\cos90^o=0$

Thus, cos(30°) + cos(60°) > cos(90°) and they are not equal to each other.