ANSWER
9.6
EXPLANATION
The given trigonometric equation is:
[tex] \cos(21 \degree) = \frac{9}{y} [/tex]
We want to find y, so we multiply both sides by y to get,
[tex]y\cos(21 \degree) = \frac{9}{y} \times y[/tex]
Cancel out the common factors,
.
[tex]y\cos(21 \degree) = 9[/tex]
. Divide both sides by cos(21°)
[tex]y= \frac{9}{\cos(21 \degree)} [/tex]
[tex]y = 9.64[/tex]
To the nearest tenth, y=9.6
