Mixed Practice Find J-dr. Find 4x-3x+5dx. Evaluate dr. A curve has gradient given by 3-8x and passes through the point (1.3). Find the equation of the curve. Find the value of a such that de 2-dr = 9. The graph of y=9x-x2-8 is shown in the diagram. Given that the shaded area equals 42.7, find the value of b correct to one decimal place. The diagram shows the graph of y=-x+9x2-24x+20. a Find the coordinates of P and Q b Find the shaded area.