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Square root function

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Graph the Square Root Function

The graph of y = √x starts at the origin and curves gently upward through (1, 1), (4, 2) and (9, 3); it only exists for x ≥ 0.

Graph of y = √x starting at the origin and curving slowly upward to the right, next to the parabola y = x².
y = √x (purple) and y = x² (red).

At a glance

What it isGraph y = √x online and learn its domain, range and key points (0,0), (1,1), (4,2), (9,3). Compare it with y = x². Free graphing calculator.
TypeInteractive guide with a calculator
LevelHigh school and college
PriceFree, with no account or sign-up
Works offlineYes, after the first visit; installs as an app
Made byAalok (aalok.builds@gmail.com)
Last updated1 November 2026

Key facts

Domainx ≥ 0
Rangey ≥ 0
Key points(0, 0), (1, 1), (4, 2), (9, 3)
Inverse ofy = x² for x ≥ 0 (mirror image in the line y = x)

How do you shift the square root graph?

y = √(x − h) + k starts at the point (h, k) instead of the origin. A minus sign outside, y = −√x, flips the curve below the x-axis.

How to use it in Plotline

  1. The graph of y = √x together with y = x² for comparison is already loaded above. Edit the equation in the list to change it.
  2. Drag the graph to move around, scroll or pinch to zoom, and tap the crosshair to reset the view.
  3. Hover over or tap the curve to read the coordinates of any point.
  4. Press Enter to add another equation and compare graphs in different colors.

Frequently asked questions

Why does y = √x stop at x = 0?

Because the square root of a negative number is not a real number, so there are no points to the left of the origin. The domain is x ≥ 0 and the range is y ≥ 0, which is why the curve starts at (0, 0) and only rises to the right.

Is it free?

Yes. The graphing calculator is free with no account and no sign-up: plot as many equations as you like, use sliders, save graphs in your browser and share them by link. It installs as an app and keeps working offline.

Learn more

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