Question

The terminal side of angle θ intersects the unit circle in the first quadrant at (925,y). What are the exact values of sinθ and cosθ?

Answer 1

Correct question is;

The terminal side of angle θ intersects the unit circle in the first quadrant at (9/25,y). What are the exact values of sinθ and cosθ?

Answer:

sinθ = (√544)/25) and cosθ = 9/25

Step-by-step explanation:

We are given that (9/25,y) lies on the unit circle. Thus, from general representation of equation of a circle, we can write that;

(9/25)² + y² = 1²

y² = 1 - (9/25)²

y² = (625 - 81)/25²

y² = 544/25²

y = ±(√544)/25

We are told the point is in the first quadrant and so we will choose the positive value of y = (√544)/25.

Therefore, the terminal side of the angle θ intersects the unit circle at [9/25, (√544)/25)]

In unit circle geometry, cosθ = x, while sinθ = y.

Thus; sinθ = (√544)/25) and cosθ = 9/25