Derivative of √x

ddx[x]=12x\frac{d}{dx}\left[\sqrt{x}\right] = \frac{1}{2 \sqrt{x}}

Write √x as x^(1/2), then apply the power rule. The slope becomes infinite as x → 0⁺, where the curve starts out vertical.

Derivation

  1. Power rule

    d/dx[xⁿ] = n·xⁿ⁻¹.

    ddx[x]=12x\frac{d}{dx}\left[\sqrt{x}\right] = \frac{1}{2 \sqrt{x}}
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  • f(x) = √x
  • f′(x)

Drag the graph · at x = 3.91 the slope is 0.25286, the height of the dashed curve.

Open in the derivative calculator

Questions students ask

What is the derivative of √x?

ddx[x]=12x\frac{d}{dx}\left[\sqrt{x}\right] = \frac{1}{2 \sqrt{x}}.

What is the second derivative of √x?

Differentiate again: d2dx2[x]=−14x32\frac{d^2}{dx^2}\left[\sqrt{x}\right] = -\frac{1}{4 x^{\frac{3}{2}}}.

What is the slope of √x at x = 3.6?

Plug into the derivative: f′(3.6)=0.263523f'(3.6) = 0.263523. That is the slope of the tangent line there; drag the graph to see it.

How do you find the derivative of √x?

Write √x as x^(1/2), then apply the power rule. The slope becomes infinite as x → 0⁺, where the curve starts out vertical.

What is the integral of √x?

See the integral of √x page for the antiderivative with steps.