(Last Updated On: January 20, 2020)

#### Problem Statement: ECE Board April 1999

(cos A)^4 – (sin A)^4 is equal to ______.

- A. cos 4A
- B. cos 2A
- C. sin 2A
- D. sin 4A

#### Problem Answer:

(cos A)^4 – (sin A)^4 is equal to **cos 2A**.

#### Latest Problem Solving in Plane Trigonometry Problems

More Questions in: Plane Trigonometry Problems

#### Online Questions and Answers in Plane Trigonometry Problems

Please do Subscribe on YouTube!

P inoyBIX educates thousands of reviewers and students a day in preparation for their board examinations. Also provides professionals with materials for their lectures and practice exams. Help me go forward with the same spirit.

“Will you subscribe today via YOUTUBE?”