Help with these two problems would be great:

Find the angle of revolution in degrees needed to put the conic in standard form. 2x^2-xy-3y^2-2x+4y-6=0

My work:

Modeling Cot2A= (A-C)/B

Cot2A= (2-(-)3)/-1 so Cot2A= (2+3)/-1 = 5/-1 = -5

I am very confused on how to go from here get the angle in degrees from a -5, any help please?

I know this isn't right but here goes,

Cot2A=-5 so Cot A = -25 degrees???

Find the equation for the conic in standard form and identify the conic.

x= 5 + 2 Cos t, y= -2 + sin t, 0 ≤ t ≤ 2π.

Do not really know what this means or where to start...

Thanks a lot for help!