4. Give the equation of the reflection, L', of the line L across the line y = x, where L is given by the equation x = 3. The line L is a vertical line. What kind of a line is L'? 5. Let f be the function given by f(x) = (a) Determine a formula for f-1(x). x +3 4x-5 (b) Determine the domain and range of f and of f1. 6. Identify an equation for the circle, C, that contains the point (5,9) and has center equal to (2,5). 7. Take C to be the circle of radius 1 centered at (0, 0). Identify and sketch all points on the circle with y-coordinate 1/2.