Question 66345
Expand <BR> Expand  (1-3x)e^3x as far as the term x^4 using a 

power series for e^x.=1+X+(X^2/2!)+(X^3/3!)+(X^4/4!)+.....

HENCE(1-3X)E^X=(1-3X)[1+X+(X^2/2!)+(X^3/3!)+(X^4/4!)+.....]
=1+X+(X^2/2!)+(X^3/3!)+(X^4/4!)+.....-3X-3X^2-(3X^3/2!)-(3X^4/3!)..TAKING TERMS UP TO X^4 ONLY
=1-2X-(5X^2/2)-(4X^3/3)-(11X^4/24)



I`m stumped, I can work it out whe n figures are involved, but add x`s y`s etc, clueless!! Thanks