Question

If x>1, which of the following increase(s) as x increases?

1. x-1/x

II. 1/x^2-x

III. 4x^3-2x^2

(A) Only I
(B) Only II
(C) Only III
(D) Only I and III
(E) All

Answer 1

Is this a calculus question? :D

Answer 2

Umm...I think soo..Not sure..

Answer 3

Derivatives? :)

Answer 4

Dont know what that is...

Answer 5

We have a problem then... lol let's see..

Answer 6

What's the second one, by the way?
\[\Large \frac1{x^2}-x\]? :D

Answer 7

Close. ^^

But the "-x" goes on the denominator..

Answer 8

Close is just a fancy word for 'wrong' XD
\[\Large \frac1{x^2 - x}\]

Answer 9

Okay, so let's look at the first one, and analyse a bit...
\[\Large \frac{x-1}{x}\]
look good? :D

Answer 10

Yes =p

Answer 11

Right, this can be simplified into
\[\Large \frac{x-1}x = \frac{x}x - \frac1x = 1 - \frac1x\] catch me so far?

Answer 12

noo...I get the first and the last one but not the middle one..

Answer 13

Well...
\[\Large \frac{x-1}x= \frac1x(x - 1) = \frac{x}x-\frac1x\] :)

Answer 14

Ohhhh...........

Answer 15

What next?^^

Answer 16

Hello?

Answer 17

Could you clarify what the functions are? Maybe draw them? I'm not sure what goes in the numerator and what goes in the denominator.