Find the values of the following trigonometric ratios:
Given
⇒
⇒ cos (-1125°) = cos (1125°)
= cos (90° × 12 + 45°)
1125° lies in first quadrant in which cosine function is positive.
∴ cos (1125°) = cos (90°× 12 + 45°)
= cos (45°)
= 1/√2