# How do you graph #x^2+y^2=4#?

##### 1 Answer

See the explanantion

#### Explanation:

This is the equation of a circle with its centre at the origin.

Think of the axis as the sides of a triangle with the Hypotenuse being the line from the centre to the point on the circle.

By using Pythagoras you would end up with the equation given where the 4 is in fact

To obtain the plot points manipulate the equation as below:

Given:

Subtract

Take the square root of both sides

Now write it as

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Calculate and plot a series of points using first the positive version of this equation then repeat using the negative side.

You should then get something that looks like:

The axis scale in mine do not exactly match in scale, so the plot looks a little flattened!