Let P = (1, 3), and define j(x, y) to be the distance from P to (x, y). a) Write a formula for the function j(x, y). b) Sketch a contour plot for j with level curves for c = 1, 2, ..., 5. (Write equations for the first two curves, and identify those curves; then infer the shape of the other curves.) c) What does the graph of j look like? How do you know this by looking at the contour plot? The word 'slope' could play a role in your explanation.