Question

question
express cos y as a fraction in simplest terms.

Explanation:

Step1: Find the hypotenuse

Use the Pythagorean theorem \(a^{2}+b^{2}=c^{2}\), where \(a = 6\), \(b = 8\). So \(c=\sqrt{6^{2}+8^{2}}=\sqrt{36 + 64}=\sqrt{100}=10\).

Step2: Recall cosine definition

The cosine of an angle in a right - triangle is defined as \(\cos\theta=\frac{\text{adjacent}}{\text{hypotenuse}}\). For \(\cos Y\), the adjacent side to angle \(Y\) is \(6\) and the hypotenuse is \(10\).

Answer:

\(\frac{3}{5}\)