Please help me understand how to do this question regarding computing the slope of the line tangent to the level curve at? P, and verify that the tangent line is orthogonal to the gradient at that point. I will give good ratings, thank you so much in advance for your time and help!

x2 ,2 Consider the paraboloid ftx'y) = 9 E T and the point P(15,0l on the level curve f(X,y) =0. Compute the slope of the line tangent to the level curve at P, and verify that the tangent line is orthogonal to the gradient at that point