x Turn on thread page Beta
 You are Here: Home >< Maths

# M2 integration/differentiation watch

1. Im doing 3 c and Im unsure what method I should use to solve t^4 -6t^2 +8 =0. In my attempt i used the factor theorem to determine that t=+/-2 is a possible solution, and tried to divide the polynomial my (t-2) however I got a remainder at the end. This seems like a lot to do for three marks, is this the method we're expected to use?
Attached Images

2. (Original post by pineneedles)
Im doing 3 c and Im unsure what method I should use to solve t^4 -6t^2 +8 =0. In my attempt i used the factor theorem to determine that t=+/-2 is a possible solution, and tried to divide the polynomial my (t-2) however I got a remainder at the end. This seems like a lot to do for three marks, is this the method we're expected to use?
No, you're meant to recognise that if you let u = t^2 then you get u^2 - 6u + 8 = 0 which is an easy quadratic. Then you can back-sub u = t^2 and solve for t. (assuming that your t^4 - 6t^2 + 8 = 0 is right in the first place, haven't checked.)
3. Ahh I didn't think of trying that method, thank you both
PRSOM, zacken
Posted from TSR Mobile

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: May 8, 2016
Today on TSR

### Boyfriend slept with someone else

...we were on a break

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams