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Standard Form -- from Wolfram MathWorld

  • ️Weisstein, Eric W.
  • ️Mon Aug 25 2014

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"Standard form" is a general term used in mathematics to refer to a normalized form of an expression. The term "canonical form" is also used in certain contexts (for example, graphs).

The standard form of a line in the Cartesian plane is given by

 Ax+By=C

(1)

for real numbers A,B,C in R.

This form can be derived from any of the other forms (point-slope form, slope-intercept form, etc.), but can be seen most intuitively when starting from intercept form. Indeed, the intercept form of a line with x-intercept (a,0) and y-intercept (0,b) is given by

 x/a+y/b=1,

(2)

and so clearing denominators to obtain

 bx+ay=ab,

(3)

gives the line in standard form with A=b, B=a, and C=ab.