Hope this helps with the answer to your question :)
<h3>
Answer:</h3>
a. -(3√13)/13
<h3>
Step-by-step explanation:</h3>
The cosine can be found from the tangent by way of the secant.
tan(θ)² +1 = sec(θ)² = 1/cos(θ)²
Then ...
cos(θ) = ±1/√(tan(θ)² +1)
The <em>cosine is negative in the second quadrant</em>, so we will choose that sign.
cos(θ) = -1/√((-2/3)² +1) = -1/√(4/9 +1) = -1/√(13/9)
cos(θ) = -3/√13 = -(3√13)/13 . . . . . matches your selection A
8 hours. 125 - 5 = 120. 120 / 15 = 8. Kelly will need to tutor for 8 hours minimum to buy the dress.
