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Second derivative of a polynomial

Let f(x)=x5−4x3+2xf(x) = x^5 - 4x^3 + 2x.

Find f′′(x)f''(x).

Hint

First find f′(x)f'(x) using the power rule term by term, then differentiate again.

Step-by-step solution

Differentiate f(x)=x5−4x3+2xf(x) = x^5 - 4x^3 + 2x term by term using the power rule: f′(x)=5x4−12x2+2f'(x) = 5x^4 - 12x^2 + 2.

Differentiate f′(x)f'(x) again term by term: f′′(x)=20x3−24xf''(x) = 20x^3 - 24x.

Third derivative of a polynomial

Find f′′′(x)f'''(x).

Hint

Differentiate the second derivative f′′(x)=20x3−24xf''(x) = 20x^3 - 24x one more time using the power rule.

Step-by-step solution

Starting from f′′(x)=20x3−24xf''(x) = 20x^3 - 24x, apply the power rule term by term one more time.

This gives f′′′(x)=60x2−24f'''(x) = 60x^2 - 24.

Constant term in the third derivative

Hint
Step-by-step solution

In f′′′(x)=60x2−24f'''(x) = 60x^2 - 24, the constant term (the number standing alone without any xx) is −24-24.

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