Question

What is the value of sin² 45° + cos² 45° ?

• A. -1
• B. 2
• C. 1
• D. 0

Answer 1

Answer:

C. 1

Solution:

Given:

sin² 45° + cos² 45°

Formula:

sin² A + cos² A = 1

Calculation:

∴ sin² 45° + cos² 45° = 1

Alternate Method

sin45° = cos 45° = 1/√2

∴ sin² 45° + cos² 45° = (1/√2)² + (1/√2)² = 1/2 + 1/2 = 1