BC 1 Derivatives Name: The Chain Rule This activity sheet is designed to help you to discover a general rule for differentiating the composition of two or more functions. As a review, let’s consider some of the rules for derivatives we have seen so far that involve variable expressions other than just x. Fill in each of the following (assume k and n are constants). y = (x + k)n y = y = (kx)n y = y = e xk y = y = e kx y = y = ln(x + k) y = y = ln(kx) y = y = sin(x + k) y = y = sin(kx) y = Now let’s step things up a bit. Fill in each blank with what you believe will be the derivative of the given function. Then in the space provided, write the derivative provided by the TI-89. Hopefully they will match, eventually. Your derivative (1.1) y = (3x + 4)10 (1.2) y TI-89 derivative y = y = 5 x 7 4 y = y = (1.3) y = (x2 – 11x + 1)5 y = y = (1.4) y x3 1 y = y = (2.1) y = ln(3 – 4x) (2.2) y e4 x (2.3) y sin (2.4) y cos x3 4 x 2 1 IMSA BC 1 2 6 2 x x 4 3 y = y = y = y = y = y = y = y = Chain Rule.1 Rev. F07 BC 1 Derivatives Name: The Chain Rule Your derivative TI-89 derivative (3.1) y = (ln (x))5 y = y = (3.2) y 3 cos x y = y = (3.3) y e y = y = (3.4) y = 5 sin3(2x) y = y = (4.1) y = etan x y = y = (4.2) y =ln(cos x) y = y = (4.3) y sec e x y = y = (4.4) y = sin4(ln(x)) y = y = 10 x 4 Given what you have seen so far, write a description of how you could take the derivative of the composite of two functions. Then complete the statement at the bottom of the page. Chain Rule: If k(x) = ƒ(g(x)), then k(x) = IMSA BC 1 Chain Rule.2 Rev. F07 Now it’s your turn! Use the chain rule to differentiate each of the following functions. Do not simplify. (1) y = (2x + 7)14 y = (2) y = 5(x3 + 1)–2 y = (3) y = 2(3x5 – 6x2 + 18)23 y = y = (4) 2 1 y x 4 3 x 3 1 5 (5) y= 2 x y = (6) y = ln(4x2 + 3x – 1) y = (7) y = (tan x)–4 y = (8) y = 4 sec5(x) y = (9) y = cos(5x2 – 3x + 2) y = IMSA BC 1 Chain Rule.3 Rev. F07 ( x 2 1)3 4x 3 (10) y= (11) y = (5x – 4)3 · (x4 + 1)2 y = y = y = y = (12) y = cot2(x) · tan 4x y = (13) y= sin 3 x cos 4 x y = (14) (15) y = (ln(6x + 2))3 y= e IMSA BC 1 cos x 2 Chain Rule continued.2 Rev. F07