Respuesta :

[tex]\bf (\stackrel{a}{4}~,~\stackrel{b}{-\sqrt{33}})\impliedby \textit{let's find the hypotenuse} \\\\\\ \textit{using the pythagorean theorem}\\\\ c^2=a^2+b^2\implies c=\sqrt{a^2+b^2}\qquad \begin{cases} c=hypotenuse\\ a=adjacent\\ b=opposite\\ \end{cases} \\\\\\ c=\sqrt{4^2+(-\sqrt{33})^2}\implies c=\sqrt{16+33}\implies c=\sqrt{49} \\\\\\ cos(\theta )=\cfrac{\stackrel{adjacent}{4}}{\stackrel{hypotenuse}{\sqrt{49}}}[/tex]

and now, let's rationalize the denominator, 

[tex]\bf \cfrac{4}{\sqrt{49}}\cdot \cfrac{\sqrt{49}}{\sqrt{49}}\implies \cfrac{4\sqrt{49}}{(\sqrt{49})^2}\implies \cfrac{4\sqrt{49}}{49}[/tex]
from the coordinates  this angle is in the  4th quadrant

Hypotenuse  = sqrt (4^2 + 33)  = sqrt 49 = 7

cos θ = 4/7