Quadratic Equations and Substituting "Appropriately?"
I have a section in my book that is asking me to "make an appropriate substitution" for a set of problems; and the book doesn't even give examples on how to do this sort of thing.
Re: Quadratic Equations and Substituting "Appropriately?"
Originally Posted by annon25
I have a section in my book that is asking me to "make an appropriate substitution" for a set of problems; and the book doesn't even give examples on how to do this sort of thing.
Here is one for example:
x^4-5x^2+4=0
Help, anyone?
Thanks
They want you to make a substitution (let's use "k", as Quacky suggests) so that your equation can be written as
ak^2 + bk + c = 0.
With k = x^2, we have
k^2 - 5k + 4 = 0
(k .... )(k ....) = 0
etc.