Home page for accesible maths 1 1 Further Integration

Style control - access keys in brackets

Font (2 3) - + Letter spacing (4 5) - + Word spacing (6 7) - + Line spacing (8 9) - +

1.3 Dividing polynomials

If the polynomials have (degree⁢f)≥(degree⁢g)({\hbox{degree}}\,f)\geq({\hbox{degree}}\,g), then we can use polynomial long division to write

f⁢(x)g⁢(x)=q⁢(x)+r⁢(x)g⁢(x){\frac{f(x)}{g(x)}}=q(x)+{\frac{r(x)}{g(x)}}

where q⁢(x)q(x) is a polynomial and r⁢(x)r(x) is a polynomial with (degree⁢r)<(degree⁢g)({\hbox{degree}}\,r)<({\hbox{degree}}\,g). (See MATH111, Thm. 7.1.10 for a proof.) It is easy to integrate the polynomial q⁢(x).q(x).

Example.

For f⁢(x)=x6+12⁢x2+39⁢x-44f(x)=x^{6}+12x^{2}+39x-44, g⁢(x)=x3+x2+3⁢x-5g(x)=x^{3}+x^{2}+3x-5 we have 𝑑𝑒𝑔𝑟𝑒𝑒⁢f=6>𝑑𝑒𝑔𝑟𝑒𝑒⁢g=3{\hbox{degree}}\,f=6>{\hbox{degree}}\,g=3. In this case we have

f⁢(x)g⁢(x)=x3-x2-2⁢x+10+3⁢x2-x+6x3+x2+3⁢x-5{\frac{f(x)}{g(x)}}=x^{3}-x^{2}-2x+10+{\frac{3x^{2}-x+6}{x^{3}+x^{2}+3x-5}}