  ## Encyclopedia > Quartic equation

Article Content

# Quartic equation

A quartic equation is the result of setting a quartic function[?] to zero, an example quartic equation is the equation

2x4+4x³-26x²-28x+48=0,

the general form is

a4x4+a3x³+a2x²+a1x+a0=0, and a4≠0.

A quartic equation always has 4 solutions (or roots).They may be complex or there may be duplicate solutions.

It is the highest degree of polynomial equation for which exact values of the roots can be found, by taking nth roots, and use of the normal algebraic operators.

If a0=0, then one of the roots is x=0, and the other roots can be found, by dividing by x, and solving the resulting cubic equation, a4x³+a3x²+a2x+a1=0.

Otherwise, divide the equation by a4, to get an equation of the form

x4+ax³+bx²+cx+d=0.

Substitute x=t-a/4, to get an equation of the form

t4+pt²+qt+r=0.

Then find the roots somehow. (To be written.)

All Wikipedia text is available under the terms of the GNU Free Documentation License

Search Encyclopedia
 Search over one million articles, find something about almost anything!

Featured Article
 Autocracy ...     Contents Autocracy Autocracy is a form of government which resides in the absolute power of a single individual. The term can ...  