Find the values of the following trigonometric ratios:
Given 
⇒ 855° = 90° × 9 + 45°
855° lies in the second quadrant in which the cosine function is negative.
∴ cos 855° = cos (90° × 9 + 45°)
= -sin 45°
1
Find the values of the following trigonometric ratios:
Given
⇒ 855° = 90° × 9 + 45°
855° lies in the second quadrant in which the cosine function is negative.
∴ cos 855° = cos (90° × 9 + 45°)
= -sin 45°