<p>What is the coefficient of x^17 in the expansion of x^5(1-x^2)^12?
answer is -924........no idea how to answer this PLEASE HELP</p>
<p>are you sure its -924? </p>
<p>well heres what you do. expand ( 1 - x^2 ) ^ 12 using a grapher . </p>
<p>you would get something like ( x^24 - 12x^22 + 66x^20 ..... ) </p>
<p>next step would be to multiply it by x^5 which would take some time so just find the coefficient of x^ 12 because x^12 * x^ 5 = x^ 17 ..</p>
<p>get it?</p>
<p>or if you feel like being real fancy, using Pascal's triangle. Althought a calculator will take much less time</p>
<p>are we talking about the ti83? this problem looks too complicated for my calc. any instructions to what to do on the calc?</p>
<p>substitue x^2 to y</p>
<p>so it will be expand(1-y)^12 then find x^6 coeficcient. </p>
<p>ilikemoo: look to see if you calc has the expand() function because i use ti-89 and i dont know what functions are incl in ti-83</p>