[tex] \sin = \frac{y}{r} \\ \\ \tan = \frac{y}{x} \\ \\ \cos = \frac{x}{r} \\ \\ {x}^{2} + {y}^{2} = {r}^{2} [/tex]
[tex] - \sin = \frac{ - 1 \: = \: y}{4 \: = \: r} [/tex]
[tex]15 \sqrt{15} = \frac{1}{x} \\ \\ x = .017[/tex]
[tex] \cos = \frac{.017}{4} = .0043[/tex]