Q. For the following equation, evaluate f′(2).f(x)=−x4+5xAnswer:
Identify Function: Given the function f(x)=−x4+5x, we need to find the derivative of the function, which is denoted by f′(x). The derivative of a function gives us the rate at which the function's value changes at any given point.
Apply Power Rule: To find f′(x), we will use the power rule for differentiation, which states that the derivative of xn with respect to x is n∗x(n−1). We will apply this rule to each term in the function separately.
Combine Derivatives: The derivative of the first term −x4 with respect to x is −4x3 (using the power rule). The derivative of the second term 5x with respect to x is 5 (since the derivative of x is 1 and 5 is a constant).
Evaluate at x=2: Combining the derivatives of both terms, we get f′(x)=−4x3+5.
Calculate Final Value: Now we need to evaluate f′(x) at x=2. We substitute x with 2 in the derivative we found: f′(2)=−4(2)3+5.
Calculate Final Value: Now we need to evaluate f′(x) at x=2. We substitute x with 2 in the derivative we found: f′(2)=−4(2)3+5. Calculating the value, f′(2)=−4(8)+5=−32+5=−27.
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