Given that sin (5x-28)° = cos (3x-50)", 0°≤ x ≤ 90°, find the value of x.

  • A 39
  • B 32
  • C 21
  • D 14
waec 2022mathematics

The correct answer is B. 32

using the trial method by inserting each option in the equation.

Inserting 21º: sin([5 x 21] - 28) = cos([3 x 21] - 50)

sin(105 - 28) = cos (63 - 50)

sin 77º = cos 13º 

where:

sin 77º = 0.9744

cos 13º =  0.9744

Previous question Next question