how to find the x intercept of a function

dCode

Search for a tool

X-Intercept

Tool for calculating the x-intercept (intercept with the x-axis) of a function, or line from at least 2 points or from 1 point and the slope coefficient.

Results

X-Intercept - dCode

Tag(s) : Geometry, Functions

dCode and more

dCode is free and its tools are a valuable help in games, maths, geocaching, puzzles and problems to solve every day!
A suggestion ? a feedback ? a bug ? an idea ? Write to dCode!

X-Intercept

Mathematics
Geometry
X-Intercept

X-Intercept Calculator

Y-Intercept Calculator

Slope coefficient calculator

Answers to Questions (FAQ)

What is the x-intercept? (Definition)

The x-intercept is the name given to the intersection point of the function/line with the x-axis (abscissa) for the ordinate value y = 0 (origin).

How to calculate the x intercept?

With the equation

For any function (not necessarily affine/linear), calculating the x intercept is calculating the value for $ y = 0 $ or $ f(x) = 0 $. The value(s) obtained is/are the x-intercept(s).

Example: A curve of equation $ y=x^2-1 $, with $ y = 0 $ is solved $ x = 1 $ or $ x = -1 $, so there are 2 x-intercepts (called the roots of the polynomial)

For an equation of a line (in the 2D plane), the equation has the form $ y = a x + b $, finding $ y = 0 $ is solving $ a x + b = 0 $ so $ x = -b/a $

With 2 points (line only)

Knowing 2 points belonging to the line, it is possible to find its equation (see the linear equation calculator) in order to deduce the x-intercept (see above)

With the slope coefficient and 1 point (line only)

Knowing the slope coefficient of a line and one of the points belonging to it, it is possible to calculate the equation of this line (see the page on the calculation of linear equations) and therefore, with this equation, deduce the x-intercept (see above).

Source code

dCode retains ownership of the online "X-Intercept" source code. Except explicit open source licence (indicated CC / Creative Commons / free), the "X-Intercept" algorithm, the applet or snippet (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, translator), or the "X-Intercept" functions (calculate, convert, solve, decrypt / encrypt, decipher / cipher, decode / encode, translate) written in any informatic language (Python, Java, PHP, C#, Javascript, Matlab, etc.) and all data download, script, copy-paste, or API access for "X-Intercept" are not public, same for offline use on PC, tablet, iPhone or Android ! Remainder : dCode is free to use.

Need Help ?

Please, check our dCode Discord community for help requests!
NB: for encrypted messages, test our automatic cipher identifier!

Questions / Comments

Summary

Source : https://www.dcode.fr/x-intercept