Q. Find the derivative of the following function.y=89x5−5x4Answer: y′=
Identify Function Components: Identify the function and its components.We have y=89x5−5x4. This is an exponential function with a base of 8 and an exponent of 9x5−5x4.
Apply Chain Rule: Apply the chain rule for derivatives.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.Here, the outer function is a(u)=8u and the inner function is u(x)=9x5−5x4.
Derivative of Outer Function: Find the derivative of the outer function a(u)=8u with respect to u. The derivative of au with respect to u is au⋅ln(a), where a is a constant and u is the variable. So, a′(u)=8u⋅ln(8).
Derivative of Inner Function: Find the derivative of the inner function u(x)=9x5−5x4 with respect to x. The derivative of 9x5 with respect to x is 45x4, and the derivative of −5x4 with respect to x is −20x3. So, u′(x)=45x4−20x3.
Apply Chain Rule with Derivatives: Apply the chain rule using the derivatives from steps 3 and 4.y′=a′(u)⋅u′(x)y′=(89x5−5x4⋅ln(8))⋅(45x4−20x3)
Simplify Derivative: Simplify the expression for the derivative.y′=89x5−5x4⋅ln(8)⋅(45x4−20x3)This is the final form of the derivative.
More problems from Find derivatives of radical functions