• Oct 29th 2008, 08:27 AM
NotanotherNickname
I think this is the right place to post this, I'm in England and don't know how the American schooling system works, but here goes:

"Find the values of k for which kx(sq)+8x+k = o has equal roots."

I know that for this equation to have equal roots the discriminant must equal zero, so:

b(sq)-4ac = 0

Putting numbers into this I get:

64-4k(sq) = 0

64=4k(sq)

This is where i get stuck - do I first square root each side, giving:

8=4k

and getting an answer 2, or do I first divide each side by 4, giving:

16=k(sq)

and getting 4 as the answer?

So to sum up, do I square root first, or simplify first?

• Oct 29th 2008, 08:34 AM
Henderson
Order of operations, if you had a value for k, would be to square first, then multiply by 4.
To undo it then (solving for k), you need to divide by 4 first, then square root.
• Oct 29th 2008, 10:31 AM
NotanotherNickname
thank you : )

how do I properly "thank" you?

(I'm new here)

-EDIT-

Don't worry, found it : )