Identify function: Identify the function to differentiate.We need to find the derivative of the function f(x)=x31 with respect to x.
Apply power rule: Apply the power rule for differentiation.The power rule states that the derivative of xn with respect to x is n∗x(n−1). In this case, n=31, so the derivative of x31 is (31)∗x(31−1)=(31)∗x−32.
Simplify derivative: Simplify the expression for the derivative.The derivative simplifies to f′(x)=(31)⋅x(−32).
Evaluate at x=8: Evaluate the derivative at x=8.Substitute x with 8 in the derivative to get f′(8)=(31)⋅8(−32).
Calculate 8(−2/3): Calculate 8(−2/3).Since 8=23, we can rewrite 8(−2/3) as (23)(−2/3)=2−2=1/(22)=1/4.
Multiply coefficient: Multiply the coefficient by the result from Step 5.Now, f′(8)=(31)∗(41)=121.