# What's the name of the following method for dividing polynomials? It's not long-division nor synthetic division

I saw this method in some random PDF and am intrigued of the exact method used. I can't find any page of this method on the web because I'm not sure what you'd call this method.

Here is the method:

For solving $$\int \frac{2x^4 + x^3}{x^2 + x - 2} \,\text{d}x$$ Observe that \begin{align*} 2x^4 + x^3 &= 2x^2 (x^2+x-2) - x^3+4x^2 \\ &= 2x^2 (x^2+x-2) - x(x^2+x-2) + 5x^2-2x \\ &= 2x^2 (x^2+x-2) - x(x^2+x-2) + 5(x^2+x-2) - 7x+10 \\ &= (2x^2-x+5)(x^2+x-2) - 7x+10 \end{align*} and then $$\int \frac{2x^4-x^3}{x^2+x-2} \,\text{d}x = \int (2x^2-x+5)\,\text{d}x + \int \frac{-7x+10}{x^2+x-2}\,\text{d}x$$

• In fact it is precisely the (Euclidean) polynomial division algorithm, except it's performed explicitly in equational form, rather than having the equations be implicit in some tabular format. Jan 15, 2017 at 23:52
• @TheGreatDuck No, that requires you to factor the denominator, which was never done. Jan 16, 2017 at 0:56
• @BillDubuque I had seen the implicit algorithm before, but it is much more enlightening to see it done this way. Are there any sources you could reccommend that explore this topic further?
– Ovi
Mar 8, 2017 at 18:02
• @Ovi What precisely are you interested in exploring further? Mar 8, 2017 at 18:42
• @BillDubuque Sorry for the ambiguity, I am wondering if you have any nice sources about how various implicit algorithms have been derived, and which is the most efficient one.
– Ovi
Mar 8, 2017 at 18:49