Evaluate: Sin2 35° - Cos2 55°

Evaluate: sin² 35° - cos² 55°

Sum

sin² 35° - cos² 55°
= sin² 35° - [cos(90° - 35°)]²
= sin²35° - sin²35°
= 0

shaalaa.com

Is there an error in this question or solution?

Chapter 21: Trigonometrical Ratios [Sine, Consine, Tangent of an Angle and their Reciprocals] - EXERCISE 21 (F) [Page 334]

Chapter 21 Trigonometrical Ratios [Sine, Consine, Tangent of an Angle and their Reciprocals]
EXERCISE 21 (F) | Q 3. (ii) | Page 334