9. Give the Polar coordinate of the plotted point in the figure. (3marks) I 20' _ \"I\" I 50" _ . 30" 27W 10. Express the equation y2 = 6x in polar coordinates. (3marks) 11. At what point is 1 the slope of the tangent line to the curve y=x2 +3x-7? (3marks) 12. Find the equation of the tangent to y=x3 -2x-1 at the point (3,2). (3marks) 13. Find the equation of the normal to y=x3 -2x-1 at the point (3,2). (3marks) 14. At a certain instant, the value of x is 5, and the value of y is 6. A short time later, the value of x has increased to 5.03, and the value of y has increased to 6.06. What is the estimated dy/dx? (5marks) 15. Suppose that y=5x2 +2x, what is the formula of dy in terms of x and dx? (5marks) 16. Suppose that y=5x2 +2x, a short time later, the value of x has increased from 4 to 4.03. Using differentials, what is the estimated corresponding increase in the value of y? (5marks)