Homework Help: Math Help:Reciprocal & Graphing

1. Dec 10, 2004

Raza

What would be the reciprocal of the following:

$$A)y=x^2$$

$$B)y=\sqrt{x}$$

I think the reciprocal for A, it would be:

$$y=\frac{1}{x^2}$$

And B would be:

$$y=\sqrt{\frac{1}{x}}$$

And also, How would I graph this?
I just need the table of values. Well, I need to do domain,range,graphing and a summary but I think I can do that myself if I get how to do the table of values.

Thanks

2. Dec 11, 2004

Gokul43201

Staff Emeritus
If you are talking about reciprocals of numbers, then yes, the reciprocals of $x^2~and~`\sqrt(x)~are~\frac{1}{x^2}~and~\frac{1}{\sqrt(x)}$

Since no domain has been provided in the question, you have to come up with what you think will be a relavant domain- ie : one which includes any "important" behavior.

For $y = x^2$, I would pick a bunch of numbers say, from the set [-10, 10].

3. Dec 11, 2004

futb0l

oops - lol nvm.

4. Dec 11, 2004

Raza

Would this be the graph:

The blue one is $$\frac{1}{x^2}$$ and the red one is $$\sqrt{\frac{1}{x}}$$

5. Dec 11, 2004

HallsofIvy

One question: since if f(x)= x2 (for x>= 0), then f-1(x)= &sqrt;(x) are the functions you give, are you sure it is "reciprocal" that is intended rather than the inverse function?

6. Dec 11, 2004

Raza

7. Dec 11, 2004

Nylex

He means are you sure you're meant to be doing 1/y or should you be finding the inverse function (eg. the inverse of multiplication is division, the inverse of squaring is square rooting)?

8. Dec 11, 2004

Raza

I am sure that I don't have to find the inverse function.

Last edited: Dec 11, 2004