Question

Use the equation Sin (2x -9) = Cos (x+30) to solve for x. Remember that these are complementary angles!

Answer 1

Well, if the two angles are complementary, then that means that

(2x -9)° + (x + 30)° = 90°

$\bf 3x+21=90\implies 3x=69\implies x=\cfrac{69}{3}\implies x=23$