Question

Find the reference angle given: t= -5π/3.

Answer 1

Answer:

The reference angle is $\frac{\pi}{3}$

Step-by-step explanation:

The given angle is $t=-\frac{5\pi}{3}$

The reference angle is the acute angle, that a given angle  makes with the x-axis.

First let us make a sketch of the given angle. See diagram in attachment.

Let $\theta$ be the reference angle of  $t=-\frac{5\pi}{3}$

Then, from the diagram, we need to subtract $\theta$ from $-\frac{5\pi}{3}$ to get to $-2\pi$.

We can therefore write the following equation and solve for $\theta$.

$\Rightarrow -\frac{5\pi}{3}-\theta=-2\pi$

We group like terms to get,

$\Rightarrow -\theta=-2\pi +\frac{5\pi}{3}$

We collect LCM to get,

$\Rightarrow -\theta=\frac{-6\pi+5\pi}{3}$

We simplify to get,

$\Rightarrow -\theta=-\frac{\pi}{3}$

We divide through by $-1$

$\theta=\frac{\pi}{3}$ to get,

The correct answer is D.