# Factoring Help

1. Oct 4, 2005

### navee

How can we factor a question which is too the power of 4 or quartic. for example ax^4+bx^3+cx^2+dx+e, but a has a grreater value than 1.

2. Oct 4, 2005

### shaner-baner

I'm not sure, but I think that fourth order equations are solvable with some weird equation like third order. In practice, you might start with the rational zeros test. What you do is: take all possible factors of 'e' and divide by all possible factors of 'a'. Then test these to see if they are zeros (if q is a zero, x-q is a factor). Using a procedure called synthetic division lets you use the factors that you find to reduce the order of the equation. When the equation has finally been reduced down to a quadratic, then you can use the quadratic formula. Alternately, there are 'numerical' methods that can find approximations of the zeros, (i.e. Newtons Method). There are a few other tricks. For example. If it looks like ax^4+bx^2+c, you can just use the quadratic formula to solve for x^2, and then take the square root of your answers.