Find the equations for the tangent line and normal line to the circle at the indicated points. (4,3)(-3,4)

x^2 + y^2 = 25

Which coordinate set do I use to find both lines? Because I get a different answer for the normal line when I use (4,3) than when I use (-3,4)

The derivative solved implicitly is -x/y. I do not know where to go from here.

Thanks for your help!