# alg 1

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Identify the domain and range of each function:

y = 4x^2 - 3

I have no idea how to find the range and domain. Would you please explain in detail how I can determine the domain and range in the quadratic problems?

• alg 1 - ,

surely your class text has a discussion of the topic, and examples.

the domain is the set of values for which the function is defined. For all polynomials, that would be all real numbers. There is no value of x for which you cannot determine a value for y: just take 4x^2-3!

For the range, it's the set of values for y which can be produced by applying the function to x. Note that for 4x^2-3, x^2 is always positive, and is zero only for x=0. Thus, the minimum value for y is -3. Pick any x you want, and you will always get a value greater than -3. And, the; larger x gets, the larger y gets. So, the range is all reals at least -3: y>=-3.

an excellent graphing resource is

http://rechneronline.de/function-graphs/

Just enter your function and you can see what it looks like.

• alg 1 - ,