Question

The terminal side of θ passes through the point (10, 6). What is the exact value of cos θ in simplified form?

Answer 1

Answer:

$\frac{5\sqrt{34}}{34}$

Step-by-step explanation:

The formula for cos θ is a/r. A is the first number (10) and b is the second number (6). R is the hypoteneuse which can be found through r = $\sqrt{a^{2} + b^{2} }$.

In the equation you'd write that as r = $\sqrt{10^{2} + 6^{2}$ which can be simplified to $\sqrt{136$.

You end up with $\frac{10}{\sqrt{136} }$ and you simplify this by doing $\frac{10 }{\sqrt{136} } * \frac{\sqrt{136} }{\sqrt{136} }$, ending with the result of $\frac{5\sqrt{34}}{\sqrt{34} }$.

(I also got this answer right on the test.)