Question

Use a calculator to solve for theta in the given interval

Answer 1

d.
`1.82\: or\:4.46`

Explanation:

The given trigonometric equation is;

`\sec \theta=-4.0545`

Recall that;

`\cos \theta=(1)/(\sec \theta)`

`\implies \cos \theta=(1)/(-4.0545)`

`\implies \cos \theta=-0.2466`

The cosine function is negative in the second and third quadrant.

`\theta=\pi-\cos^(-1)(0.2466)\: or\:\pi+\cos^(-1)(0.2466)`

`\theta=1.82\: or\:4.46`