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Differentiation; Revision Overview. Differentiation. Given Y = ax n then differentiating . Rule Multiply by the power and take one off. Differentiation. You can be asked to write down the first and second differentials in an A/S question. Remember
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Differentiation Given Y = axn then differentiating Rule Multiply by the power and take one off
Differentiation You can be asked to write down the first and second differentials in an A/S question. Remember y = gives information about the (x,y) curve gives information about the gradient of the tangent to the curve gives information about the nature of the stationary point(s) on the curve
Differentiation: Basic rule Answer
Differentiation You can be asked to find the value of the gradient of the tangent at a given (a) point x on the curve or (b) co-ordinate point on the curve Method Step 1 differentiate to find Step 2 calculate the value of at the calculated x value
Differentiation To find the gradient write down the x coordinate i.e x = 4
Differentiation Stationary point on a quadratic curve Step 1 Differentiate and set Step 2 Solve the resulting linear equation for x Step 3 Substitute back into the curve equation to find the y co-ordinate. Step 4 Determine the nature of the turning point. Write down interpret its sign. positive implies minimum negative implies maximum
Differentiation: Stationary Point Question The curve has an equation y = 1 + 4x – x2 Calculate the coordinates of the point labelled A on the curve shown in the diagram. y A x
y A x Differentiation: Stationary Point answer Answer The curve has an equation y = 1 + 4x – x2 Differentiate Point A is a turning point i.e Y = 1 + 4(2) – (2)2 = 5 Coordinates of A (2, 5) (2, 4 ) Nature of turning point Negative Maximum
Differentiation Stationary point on a cubic curve Step 1 Differentiate and set Step 2 Solve the resulting quadratic equation for x Step 3 Substitute back into the curve equation to find the corresponding y co-ordinates. Step 4 Determine the nature of the turning points. Using the test.
Differentiation Test for the nature of the turning points Step 1 Differentiate to obtain Step 2 Substitute each x value into Step 3 If then curve takes a Minimum If then curve takes a Maximum At the two turning points
Differentiation Answer
Differentiation points turning Answer Answer continued
Differentiation Turning point Answer Graph with turning points clearly labelled. y = x3- 6x2 -15x + 1
Differentiation: Stationary Points on a curve. B Question The curve has an equation y = 5 + 3x2 – x3 Calculate the coordinates of the points labelled A and B on the curve shown in the diagram. y B y x A
Differentiation stationary points Answer Answer
Differentiation stationary points Answer Answer
Differentiation: Stationary Points on a curve. Answer Answer The curve has an equation y = 5 + 3x2 – x3 the coordinates of the points labelled A and B are: A(0,5) and B(2,9) Max B y y B(2,9) x x A(0,5) A Min
Differentiation: Stationary points on a curve. Question Calculate the coordinates of the stationary points on the curve y = x3 - 3x + 2 Determine the nature of each of the stationary points.
Differentiation stationary points Answer Answer
Differentiation stationary points Answer Answer
Differentiation: Stationary Points on a curve. Answer Answer The curve has an equation y = x3- 3x + 2 the coordinates of the turning points labelled (-1, 4) and (1, 0) y (-1,4) Max x (1,0) Min