Mathematics for IGCSE & O level - Pythagoras' Theorem And Trigonometry (Section 5 - No. 37)
Which of the following is NOT a correct statement?
sin²θ + cos²θ = 1
sin(90° - θ) = cos θ
cos(180° - θ) = cos θ
tan θ = sin θ / cos θ
คำอธิบาย
cos(180° - θ) = -cos θ