Chapter 8 - Complex Numbers, Polar Equations, and Parametric Equations - Section 8.6 Parametric Equations, Graphs, and Applications - 8.6 Exercises - Page 400: 47b

$\theta = 50.0^{\circ}$

$x = 56.56530965~t$ $x = (v~cos~\theta)~t$ We can equate the two expressions for $x$ to find $\theta$: $(v~cos~\theta)~t= 56.56530965~t$ $v~cos~\theta= 56.56530965$ $cos~\theta= \frac{56.56530965}{v}$ $\theta= arccos(\frac{56.56530965}{v})$ $\theta= arccos(\frac{56.56530965}{88})$ $\theta = 50.0^{\circ}$