If a composite function r( x) is defined as
Here, three functions— m, n, and p—make up the composition function r; hence, you have to consider the derivatives m′, n′, and p′ in differentiating r( x). A technique that is sometimes suggested for differentiating composite functions is to work from the “outside to the inside” functions to establish a sequence for each of the derivatives that must be taken.
Example 1: Find f′( x) if f( x) = (3x 2 + 5x − 2) 8.
Example 2: Find f′( x) if f( x) = tan (sec x).
Example 3: Find if y = sin 3 (3 x − 1).
Example 4: Find f′(2) if .
Example 5: Find the slope of the tangent line to a curve y = ( x 2 − 3) 5at the point (−1, −32).
Because the slope of the tangent line to a curve is the derivative, you find that
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