Question

Find the exact values

Answer 1

so hmmm notice
`\bf sin(\theta)=\cfrac{opposite}{hypotenuse}\implies sin(\theta)=\cfrac{-4\leftarrow opposite}{5\leftarrow hypotenuse}`

they hypotenuse, is just the radius, thus is never negative, since it's just a unit

now, check the picture below, that's the angle, and its reference angle

so.. use the pythagorean theorem to get the adjacent side, or "x" value

keeping in mind that
`\bf tan(\theta)=\cfrac{opposite}{adjacent} =\cfrac{y}{x} \qquad \qquad sec(\theta)=\cfrac{hypotenuse}{adjacent} =\cfrac{r}{x}`