Answer :
Given the point: (15, -15)
We will express the point in polar notation
the formulas to convert from rectangular to polar are as follows:
[tex]\begin{gathered} r=\sqrt[]{x^2+y^2} \\ \theta=\tan ^{-1}(\frac{y}{x}) \end{gathered}[/tex]so, the polar form will be as follows:
[tex]\begin{gathered} r=\sqrt[]{(15)^2+(-15)^2}=15\sqrt[]{2}\approx21.21 \\ \\ \theta=\tan ^{-1}(\frac{15}{-15})=tan^{-1}(-1)=-45\degree^{} \end{gathered}[/tex]So, the answer will be:
[tex](15,-15)=21.21\angle-45\degree[/tex]