# Homework Help: Sketch this function, help?

1. Apr 25, 2014

### noahsdev

1. The problem statement, all variables and given/known data
Consider the function ƒ:-k,k→R, where ƒ(x) = 1/√(k2-x2), where k is a positive constant.
(i) Sketch the graph of y = ƒ(x)
(ii) What is the domain of the function?

2. Relevant equations
ƒ(x) = 1/√(k2-x2)

3. The attempt at a solution
I don't understand how I am supposed to solve this. Couldn't k equal anything? Why couldn't it be 1 or 2? This makes no sense.
Help is appreciated. Thanks.

2. Apr 25, 2014

### Staff: Mentor

k is an unspecified constant - a parameter. k could be 1 or 2, but you shouldn't assume that it is any specific value.

Can you sketch the graph of y = $\sqrt{k^2 - x^2}$? If you can get this graph, then the graph of f is just the reciprocal.

3. Apr 25, 2014

### LCKurtz

Just draw an x axis, mark some point on the positive side, and label it k. Then draw your graph.

4. Apr 25, 2014

### Staff: Mentor

noahsdev, after you label some point k on the positive side, label another as -k on the negative side. Then draw your graph.