I need some help with some precalculus thing.....

f(x) = x^2 -2x

find the values for which f(x) > 15
find the range of f.
42.
RIP Tom Searle.
46?? uh, its a bit of work, but could you type out the steps?? Im a bit of a dunce
x ≥ 5

I think... I failed pre cal and did this in my head.

EDIT:
Quote by Confuse-a-Cat
f(x) will be greater than 15 for any value of x greater than 5.

You can call me Aaron.

♠♣♥♦
Out on parole, any more instances of plum text and I get put back in...
Last edited by biga29 at Dec 6, 2011,
f(x) will be greater than 15 for any value of x greater than 5.
The answer is 200. Which also happens to be the wattage of the amp you need.
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Theory is descriptive, not prescriptive.

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theory states 1+1=2 sometimes in music 1+1=3.
Quote by biga29
x ≥ 5

I think, I failed pre cal and did this in my head...

It's only >5, can't equal

TS is shit at math ...
Quote by Zeletros
It's only >5, can't equal

TS is shit at math ...

Oh, ok. Because the question was for everything greater than 15, not greater than or equal to 15 right?
You can call me Aaron.

♠♣♥♦
Out on parole, any more instances of plum text and I get put back in...
Quote by biga29
Oh, ok. Because the question was for everything greater than 15, not greater than or equal to 15 right?

Yes, and also TS is shit at math
Quote by Zeletros
It's only >5, can't equal

TS is shit at math ...

I know!
ok, find the coefficient of x^4 in the expansion of (2-x^2)(1-2x^2)^8
Quote by OsmanAli
ok, find the coefficient of x^4 in the expansion of (2-x^2)(1-2x^2)^8

Ok, find the coefficient of x^4 in the expansion of (2-x^2)(1-2x^2)^8, yourself
Quote by OsmanAli
ok, find the coefficient of x^4 in the expansion of (2-x^2)(1-2x^2)^8
This isn't what your mom meant when she said to do your homework.

Also, there is a huge math thread with a bunch nerds who get boners for stuff like this.
You can call me Aaron.

♠♣♥♦
Out on parole, any more instances of plum text and I get put back in...
My atttempt at a... I'm a but rusty in the language of Mathematics.

x² – 2x > 15
x² – 2x – 15 > 0
(x – 5)(x + 3) > 0

(x - 5) <- - -(-3)- - -(5)----->
(x + 3) <- - -(-3)-----(5)----->
f(x) .. <-----(-3)- - -(5)----->

- - - Negative
----- Postive

Therefore,
f(x) > 15 when:
x < (-3) or x > 5

When x is either grater than 5 or less than negative 3.
Last edited by sfaune92 at Dec 6, 2011,
^ And now I feel rather silly for forgetting that there would also be a negative answer. That's what I get for looking at it and thinking '5' rather than working it through properly...

Quote by OsmanAli
ok, find the coefficient of x^4 in the expansion of (2-x^2)(1-2x^2)^8