Hey guys can you help me out with this:

Given the ellipse 4x^2 + 9y^2 = 36,

a) Find.

is this correct:

b) Give the equations of all tangent lines to the graph atx= 1.

at this point I plug in 1 in the original function to get y right?

I got this weird number for y when I did that:

are my calculations correct?