Need help in understanding general math concepts? Download this free eNotes guide to learn about the distance formula.
The distance formula is an equation used to find the distance between any two points on a graph. The distance formula is derived directly from the Pythagorean theorem which tells you the length of the hypotenuse c if you know the length of each of the other two sides of a triangle.
- You’ll need to know the full coordinates of two points on a graph to solve for the distance.
- Distance is always expressed as a positive number, even if some or all the coordinates of your points are found in the negative region of the graph.
- It doesn’t matter which points you choose to be the first and second pair because the distance will always come out the same.
- Be sure to pay attention when subtracting negative numbers when solving your equation. Remember that subtracting a negative number is the same as adding the same positive number.
- If the two points lie on the same x or y axis, it will often be easier to just find the difference using simple subtraction of the distance between coordinates on that shared axis. When two x or two y coordinates do not share a common axis you’ll want to use the distance equation.
- Be sure not to mix up the coordinates when substituting values into the equation—this is the most common mistake made when solving this equation.
- If your result is the square root of a number such as 4 or 9 that will give a whole number when calculated, remember to use the whole number instead of leaving the answer as a square root. If your answer is a number that does not reduce to a whole number for its square root, leave it as a square root unless asked to write it as a decimal.