When 2x^3+px^2+qx-1 is divided by (x+1), the remainder is 2>
Given that (x-2) is a factor of x^3+qx^2+px-6, find the values of p and q.
If anyone could help I would really appreciate it!
Thank you.
0
2 replies to this topic
#1
-
- Members
-
- 2 posts
Newbie
- Gender:Female
Posted 09 January 2012 - 12:04 PM
I'm new to this, but i was hoping someone would be able to help me with ths problem I've been stuck on I know it is to do with synthetic division but I'm unsure how to answer it,
When 2x^3+px^2+qx-1 is divided by (x+1), the remainder is 2>
Given that (x-2) is a factor of x^3+qx^2+px-6, find the values of p and q.
If anyone could help I would really appreciate it!
Thank you.
When 2x^3+px^2+qx-1 is divided by (x+1), the remainder is 2>
Given that (x-2) is a factor of x^3+qx^2+px-6, find the values of p and q.
If anyone could help I would really appreciate it!
Thank you.
#2
-
- Members
-
- 147 posts
Site Swot
- Location:Aberdeen
- Interests:Guitar - Passed my grade 6 :D :D<br />Write computer programs - won Heriot-Watt programming challenge 2006 and 2007 :D<br />
- Gender:Male
Posted 09 January 2012 - 12:42 PM
Yes you are right, it involves two synthetic divisions:
firstly use synthetic division dividing x+1 into 2x³+px²+qx-1 and letting the remainder (the bottom right number) equal 2.
You should end up with p-q-3=2 =>
p-q=5 (1)
second divide x-2 into x³+qx²+px-6, this time letting the remainder equal 0
so we get 2p+4q+2=0 =>
p+2q=-1 (2)
The using simultaneous equations on eqns 1 and 2 you get that p=3 and q=-2
If you need me to go through the synthetic divisions step by step I can, but try them on your own first, just take them slow and make sure you leave a lot of room between numbers cos the expressions can get long XD
Hope this helps
firstly use synthetic division dividing x+1 into 2x³+px²+qx-1 and letting the remainder (the bottom right number) equal 2.
You should end up with p-q-3=2 =>
p-q=5 (1)
second divide x-2 into x³+qx²+px-6, this time letting the remainder equal 0
so we get 2p+4q+2=0 =>
p+2q=-1 (2)
The using simultaneous equations on eqns 1 and 2 you get that p=3 and q=-2
If you need me to go through the synthetic divisions step by step I can, but try them on your own first, just take them slow and make sure you leave a lot of room between numbers cos the expressions can get long XD
Hope this helps
=-=-=Marcus=-=-=
#3
-
- Members
-
- 2 posts
Newbie
- Gender:Female
Posted 09 January 2012 - 06:41 PM
Thank you so much!!! this has helped loads .
.
1 user(s) are reading this topic
0 members, 1 guests, 0 anonymous users
