Apply Chain Rule: To find the derivative of the function g(x)=(4x3−3x2+2x−1)3, we will use the chain rule. The chain rule states that the derivative of a composite function is the derivative of the outer function evaluated at the inner function times the derivative of the inner function.
Identify Functions: First, let's identify the outer function and the inner function. The outer function is u3 where u is the inner function. The inner function is 4x3−3x2+2x−1, which can also be written as (4x3−3x2+2x−1)1/2.
Derivative of Outer Function: The derivative of the outer function u3 with respect to u is 3u2. We will later substitute u with the inner function.
Derivative of Inner Function: Now, we need to find the derivative of the inner function (4x3−3x2+2x−1)1/2. To do this, we use the power rule combined with the chain rule. The derivative of u1/2 with respect to u is 21u−1/2.
Combine Derivatives: Next, we need to find the derivative of 4x3−3x2+2x−1 with respect to x. Using the power rule, the derivative is 12x2−6x+2.
Final Derivative: Now we can combine all the parts. The derivative of the inner function with respect to x is 21(4x3−3x2+2x−1)−1/2⋅(12x2−6x+2).
Simplify Expression: Finally, we multiply the derivative of the outer function by the derivative of the inner function to get the derivative of the composite function:g′(x)=3(4x3−3x2+2x−1)2⋅21(4x3−3x2+2x−1)−1/2⋅(12x2−6x+2)
Simplify Expression: Finally, we multiply the derivative of the outer function by the derivative of the inner function to get the derivative of the composite function:g′(x)=3(4x3−3x2+2x−1)2⋅21(4x3−3x2+2x−1)−1/2⋅(12x2−6x+2)Simplify the expression by canceling out the (4x3−3x2+2x−1)−1/2 term in the derivative of the inner function with one of the (4x3−3x2+2x−1)1/2 terms in the outer function's derivative:g′(x)=3⋅21⋅(12x2−6x+2)g′(x)=23⋅(12x2−6x+2)g′(x)=18x2−9x+3
More problems from Interpret functions using everyday language