Change of variables

Under substitution is understood in mathematics generally the replacement of a term by another with the aim of transferring the output term in a readily releasable standard form. The substitution is used among other things to solve biquadratic equations or integrals to determine by means of substitution.

Example

The following example uses the substitution to the solution set of a given quartic equation or the zeros of a rational integral function or a polynomial to determine the 4th degree.

The equation

Can be explained by the substitution in

Convict. This quadratic equation can now be solved with standard methods such as the pq - formula. Is obtained as solutions. By back substitution, one obtains for

The output equation is thus as a solution in amount or in