Equation Grapher
Plot any algebraic expression of \(x\). Enter a function below, adjust the axis ranges if you want, and click Plot Expression. Drag the graph to pan; scroll to zoom.
Click to try these examples:
x²
3x + 5
sin(x)
cos(x)
x³ - 2x
sin(x)·cos(x)
e^(-x²/2)
tan(x)
√|x|
log(x)
2^x
Frequently Asked Questions
What does it mean to "graph" an equation?
A graph plots every point \((x, y)\) where \(y\) equals the value of the expression for that \(x\). For \(y = x^2\), the point \((2, 4)\) is on the graph because \(2^2 = 4\). Connecting all such points produces the curve you see.
How do I read the axes and scale?
The horizontal axis shows \(x\) values and the vertical axis shows \(y\) values. The numbers at the edges (set by the X Min/Max and Y Min/Max inputs) tell you the visible range. Tick labels along each axis mark intermediate values. Use the range inputs to zoom into a region of interest, or scroll the mouse wheel over the canvas.
How do I write an expression?
Use x as the variable, ^ for exponents, and * for multiplication (or omit it between a number and a variable, like 3x). Standard math functions work by name: sin(x), cos(x), tan(x), sqrt(x), abs(x), log(x), exp(x). Constants pi and e are recognized. So sin(x) * cos(x), sqrt(abs(x)), and exp(-x^2/2) are all valid.
What happens at points where the function is undefined?
Points where the expression returns NaN, Infinity, or -Infinity are simply skipped. For \(\dfrac{1}{x}\), the grapher draws two separate branches with no line crossing through \(x = 0\). For \(\tan(x)\), the asymptotes appear as gaps. The line you see is connected only between points where the function actually has a finite value.
Can I plot a vertical line or an implicit equation?
Not directly. This grapher plots \(y = f(x)\), so each \(x\) gives at most one \(y\). A vertical line like \(x = 3\) isn't a function of \(x\), and an implicit equation like \(x^2 + y^2 = 1\) (a circle) requires solving for \(y\) in pieces. For the circle, you'd plot \(\sqrt{1 - x^2}\) and \(-\sqrt{1 - x^2}\) as two separate graphs to see the full shape.