[Wolfman]

I imagine plenty of people want help with their math homework. I am three of them. To start out with:

21. 2/(3-i)

I know how to do this one and have done similar questions successfully, but the answer I keep getting isn't the right one, which is (3/5) + (1/5)i.

35. (-3 - √-7) ^2

Same thing. I know how to do it, but I'm not getting the right answer (2 + 6i√7)

(2/(9(x+h)^2)) - 2/(9x^2))/h

I got nothing on this.

[Nets]

Cheers.

(2/(9(x+h)^2)) - 2/(9x^2))/h

What is this?

[Wolfman]

Thanks.

[Marauder]

Could not upload the image so I'll post link.
http://s1065.photobucket.com/albums/u385/RickAlb/?action=view&current=IMG_0167.jpg
Hope it helps.

[Wolfman]

(2/(9(x+h)^2)) - 2/(9x^2))/h

What is this?

Oops, this one slipped by me.
(2/9(x+h)^2)-2/(9x^2)
---
h

Better?

[Kaiserschmarrn]

Is the (x+h) meant to be in the numerator (in the previous post is seemed to belong to the denominator)?

[Wolfman]

At this point it doesn't really matter, but it's two fractions subtracted from each other, and the both of them are over h.

[Kaiserschmarrn]

If any of the following 2, which one?
a)
b)

What do you have to do? Is this a limit?

[Wolfman]

A, reduce to (apparently):
(-4x-2h)/((9x^2)(x+h))

If that makes any sense.

[Marauder]

So, just a simplification? by the way how do you generate images of mathematical expressions and post them here?

[Kaiserschmarrn]

Ok, I see.

You need to bring this part

onto a common denominator. You will then be able to factor out h. The factored out h and the h in the (overall) denominator cancel and you are left with the expression/result you posted.

Marauder, textify.

[Marauder]

I don't think you can reduce the expression to the solution you gave, if you give random values to the variables (for example x=2 and h=3) the original expression gives a different result than the solution.

[Kaiserschmarrn]

Maybe he lost a minus sign somewhere?

Edit: No, a square in the denominator is missing. I think it should be (x+h)^2

[Wolfman]

Just double checked, nope. Wouldn't be the first time a math textbook has included the wrong answer (in my last math class the professor spent 20 minutes trying to figure out an equation, then concluded the book was wrong).

[Kaiserschmarrn]

Publius, solution should be

[Wolfman]

My notes disagree. I may have written it wrong, or it may be wrong. Either way.

[Marauder]

Publius, are you an engineering student?

[Wolfman]

Economics. This is for College Algebra. I'm not a strong math student (majoring in Econ was mistake 1), and decided for godknows what reason to take the class online (mistake 2), and then realized that was a terrible mistake and dropped the class (too late to enroll in-class, mistake 3). I'll retake it in-class next semester.

[Marauder]

I was wondering if you could give me your opinion about a couple of german universities I am interested in (I read somewhere you are from Germany), I am planning on doing a master in Germany in the area of electrical engineering.

[Wolfman]

(I read somewhere you are from Germany)

If so, someone needs to tell the rest of the cornfield in Nebraska I live in that we've joined Germany. I'm a bit of a Germanophile though, and have seriously talked about moving to Germany, so that may be what you're thinking of. However, Killim may be able to help you.

Edit: However, this forum in general may be a good resource for you.