Chapter 8 - Complex Numbers, Polar Equations, and Parametric Equations - Section 8.6 Parametric Equations, Graphs, and Applications - 8.6 Exercises - Page 400: 46b

$\theta = 20.0^{\circ}$

$x = 82.69295063~t$ $x = (v~cos~\theta)~t$ We can equate the two expressions for $x$ to find $\theta$: $(v~cos~\theta)~t= 82.69295063~t$ $v~cos~\theta= 82.69295063$ $cos~\theta= \frac{82.69295063}{v}$ $\theta= arccos(\frac{82.69295063}{v})$ $\theta= arccos(\frac{82.69295063}{88})$ $\theta = 20.0^{\circ}$