Question

express cos r as a fraction in simplest terms. answer attempt 1 out of 2 cos r = | submit answer

Explanation:

Step1: Find side QR via Pythagoras

$$QR = \sqrt{PR^2 - PQ^2} = \sqrt{10^2 - (\sqrt{63})^2} = \sqrt{100 - 63} = \sqrt{37}$$

Step2: Define cos R for right triangle

$\cos R = \frac{\text{Adjacent to } R}{\text{Hypotenuse}} = \frac{QR}{PR}$

Step3: Substitute values to simplify

$\cos R = \frac{\sqrt{37}}{10}$

Answer:

$\frac{\sqrt{37}}{10}$