"Im clueless..." (find domain of fcn: g(x) = 10x)

[Eva Barragan]

Every time I see a question about functions, I freeze. I know it's a completely simple process, but I just can't seem to grasp it. Please help.

The directions say: Find the domain of each function.

The problem is: g(x)=10x

I don't get it. Any help would be much appreciated.

-function dummy

 

[tkhunny]

What will work? That is the Domain. Often, it is easier to find what will NOT work.

What values can you multiply by 10? Are there ANY restrictions?

 

[Concorde]

Hello eva,

The domain of a function is basically all the x values a function is permited to have. Most commonly an x value is not in the domain of a function when that x value makes the denominator of a fraction 0 (we can't divide by zero rember!) or it would result in a negative result under a square root symbol (this is called an imaginary/complex number, you will learn more about later; most likely in Algebra II). The domain can also be restricted on a function so that it actually is a function (ie it passes the vertical line test).

For the function g(x)=10x the domain is all real numbers (the symbol for all real numbers is a funny looking R, I wish I could emulate it on here but I don't know how). Basically that mean any real number you choose to assign x to will not create a 0 in the denominator, a negative number under a square root sign, or cause g(x) to fail the vertical line test.

Hope that helps.

 

[Eva Barragan]

Hello concorde,
wow your explination was sooooooo helpful.
I have never had anyone explain it to me like that.
thank really. that explanation did help.


hey tkhunny!
thanks for replying ummm what are restrictions?
sorry i dont get it. :?

 

[tkhunny]

What are restrictions?

Reread Concorde's first paragraph. Some are obvious. Some are not so obvious. Some are aritrary or deliberate. Some are a surprise as you work through a given problem.