Question

SOLVE THE FOLLOWING QUESTION:-
Given that cos^ 2 theta-sin^ 2 theta= 3/4 .
What is the value of cos theta?
A. (sqrt(3))/2
B. 1/2
C. (sqrt(7))/2
D. (sqrt(7))/(sqrt(8))​

Answer 1

Answer:

B

Step-by-step explanation:

1/2 step by step explanations

Answer 2

Answer:

7 / 25

Step-by-step explanation:

tan = perpendicular/base = 3/4 Let perpendicular = 3x and base = 4x According to pythagoras theorm Hypotenuse² = perpendicular² + base²

= (3x)² + (4x)²

= 9x² + 16x²

= 25x²

Hypotenuse = √25x² = 5x

Sin = perpendicular/hypotenuse

5x = 3/5

= 3x/

cos = base/hypotenuse = 4x/5x = 4/5

cos² - sin² = (4/5)² - (3/5)²

= 16/25 - 9/25

= 7/25