The conversion is
[tex]x = r \cos \theta[/tex]
[tex]y = r \sin \theta[/tex]
So
[tex] \dfrac y x = \tan \theta [/tex]
We're given the fairly unusual
[tex] \theta = -\frac 5 2 [/tex]
It's fairly unusual because usually an angle is given in degrees or radians, and typically the radians are a fraction times pi. We'll assume radians.
[tex] \dfrac y x = \tan \theta = \tan(-5/2) \approx 0.747 [/tex]
Ah, there's our .75. The approximate answer is
[tex] y = 0.75 x[/tex]
Third choice.
The exact answer is
[tex] y = x \tan( -\frac 5 2) [/tex]
also a line through the origin.
