Created by T Madas Question 17 (**) The point P ( 3, −1) lies on the curve with equation y = f ( x ) , whose gradient function is given by f ′ ( x ) = − x2 , x ∈ » Find an equation for f ( x ) C1M , f ( x ) = + x − x3 Created by T Madas Created by T Madas Question 18 (**) y = x3 − 12 x + 45 x − 34 y B R A O x The figure above shows the curve with equation y = x3 − 12 x + 45 x − 34 The points A and B lie on the curve, where x = and x = , respectively The finite region R is bounded by the curve and the straight line segment AB Show that the area of R , shown shaded in the figure, is exactly 81 SYN-S , proof Created by T Madas Created by T Madas Question 19 (**) y= Find the value of +3 x , x > x dy at the point where x = dx MP1-K , Created by T Madas dy dx = x=4