# Thread: binomial theorem as far as the term t^3

1. ## binomial theorem as far as the term t^3

expand by the binomial theorem as far as the term $\displaystyle t^3$ , assuming that |3t| < 1; :

$\displaystyle (1 - 3t)^-2$

i know the answer is real easy i just forgotten how to do it thanks guys!.

2. The binomial series is:

$\displaystyle (1+x)^{m}=1+mx+\frac{m(m-1)}{2!}x^{2}+$$\displaystyle \frac{m(m-1)(m-2)}{3!}x^{3}+\frac{m(m-1)(m-2)(m-3)}{4!}x^{4}+...........$

Just sub in $\displaystyle m=-2, \;\ x=-3t$