the turning point of curve is when the gradient of the curve is 0. to find the gradient of the curve, we need to differentiate the curve.y = x2 + 3x - 10dy/dx = 2x + 3gradient = 2x + 3 = 02x = -3x = -1.5now we have the x coordinate of the curve turning point, sub this value back into curve equation to get y valuey = (-1.5)2 + 3(-1.5) - 10y = -12.25so coordinates of turning point = (-1.5, -12.25)