Question

what is the value of (cos square 67° - sin square 23°)

Answer 1

The answer is 0.
Convert Cos67° into Sin23°
Cos(67)° = Cos(90-23)° = Sin23°

Answer 2

Cos square 67-sin square 23

=Sin square (90-67) -sin square 23

=Sin square 23 -sin square 23

=0