Online Graphing Calculator — Plot Functions and Equations Instantly

There's something that clicks when you can see a math function instead of just staring at its equation. A parabola, a sine wave, two intersecting lines — visual context makes the algebra make sense. The CalcHub Graphing Calculator lets you plot functions directly in the browser with no software to install.

What You Can Plot

• Algebraic functions: y = 2x + 3, y = x² − 4, y = (x+1)/(x−2)
• Trigonometric: y = sin(x), y = 2cos(3x + π/4), y = tan(x)
• Exponential & Logarithmic: y = eˣ, y = 2^x, y = ln(x), y = log(x)
• Multiple functions at once: Plot y = sin(x) and y = cos(x) side by side
• Implicit equations: Circles, ellipses (x² + y² = 25)
• Piecewise functions (where supported)

How to Use It

1. Type your function in the input bar. Use standard notation: x^2 for x², sqrt(x) for √x, abs(x) for |x|.
2. The graph renders immediately as you type.
3. Use the zoom controls or scroll wheel to explore different regions.
4. Hover or tap on the curve to read off exact coordinates.
5. Add a second function to graph two at once — useful for finding intersections.

Function Notation Guide

Math Expression	Type This
x²	x^2
√x	sqrt(x)
eˣ	e^x or exp(x)
sin(x) in degrees	sin(x*pi/180)
x	abs(x)
log₂(x)	log(x)/log(2)

Useful Applications

Finding where two lines intersect: Graph y = 2x + 1 and y = −x + 7. The intersection point is where they cross — you can trace the cursor to find it (x=2, y=5), or solve algebraically and verify visually. Understanding transformations: Graphing y = sin(x), y = sin(2x), and y = sin(x/2) together shows how the period changes with the coefficient. Much clearer than trying to explain it with words. Checking calculus results: After finding a derivative by hand, graph both the original function and its derivative. The derivative should be zero at every local max/min of the original — if your graph confirms that, your calculus is right. Exponential growth and decay: Graph y = 1000 × e^(−0.1x) to visualize radioactive decay or drug concentration over time. You can read off the half-life visually.

Interpreting What You See

Feature on Graph	What It Means
x-intercepts	Roots / zeros of the function
y-intercept	Value of f(0)
Local max/min	Peaks and valleys
Asymptotes	Where the function heads toward ±∞
Increasing/decreasing sections	Sign of the derivative

Tips for Better Plots

• Set your domain intentionally: If you're graphing y = ln(x), restrict x to positive values so you don't see an error in the negative region.
• Watch your angle units: Trig functions default to radians in most graphing tools. To see a "normal" sine wave (one full cycle from 0 to 360), you're looking at 0 to 2π ≈ 6.28, not 0 to 360.
• Use zoom wisely: A function that looks like a straight line at wide zoom may reveal curves up close. Zoom in near interesting points.
• Add gridlines: Helps estimate coordinates more accurately without needing the trace tool.

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Why does my graph of tan(x) have vertical lines that shouldn't be there?

Those are asymptotes — tan(x) is undefined at x = π/2, 3π/2, etc. The lines you're seeing are the graphing calculator connecting values on either side of the asymptote, which makes it look like a vertical line. They're not real parts of the function.

Can I graph inequalities?

Some graphing tools shade the region where an inequality holds (e.g., y > x + 2). This is handy for visualizing feasible regions in linear programming problems. Check if the CalcHub tool supports shading in its current version.

How do I find the exact intersection of two curves?

Trace both curves and zoom in near the crossing point, or set the two functions equal to each other and solve algebraically. The graphical approach gives a good estimate; algebra gives the exact value.

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