Question

2 sin2 a-cos2a=2, find value of a

Answer 1

SOLUTION:

Given:

2sin²A -cos²A =2

To find:

The value of a.

Explanation:

2sin²A -cos²A =2

=) 2sin²A -cos²A =2(sin² + cos²A)

=) 2sin²A -cos²A = 2sin²A +2cos²A

=) 3cos² A=0

=) cosA= 0

A= 90°

Thank you.

Answer 2

Answer:

Step-by-step explanation:

2sin^2 a - cos^2 a= 2

⇒2sin^2 a-cos^2 a= 2(sin^2 a + cos^2 a)

⇒2sin^2 a -cos^2 a= 2sin^2 a + 2cos^2 a

⇒-cos^2 a = 2cos^2 a

⇒3cos^2 a =0

⇒cos^2 a =0

⇒a=90° or a=nπ/2