passwella.
Menu

WAEC Mathematics 1993 Question 32

Question 32

Trigonometry

Cos 75° has the same value as

  1. A.cos 115°
  2. B.cos 255°
  3. C.cos 285°
  4. D.−sin 165°
  5. E.−sin 255°
Show the answer and explanation

Answer: C (cos 285°)

Explanation

285° = 360° − 75°, and cosine is positive in the fourth quadrant, so cos 285° = cos 75°.