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Lesson · The power rule

A derivative measures how fast a function is changing. For powers of xx there is a beautiful shortcut called the power rule:

ddx(xn)=n xn−1\frac{d}{dx}\left(x^n\right) = n\,x^{n-1}

Bring the exponent down in front, then subtract one from the exponent.

Use the power rule to differentiate x3x^3.

ddx(x3)\frac{d}{dx}\left(x^{3}\right)
f′(x)=f'(x) =