Evaluating f(x)

[comprehension2]

When I have f(x)=5-3x and x=-4 and x=2 how should I begin to work this. Also when I'm supposed to find the domain and range from f(-1)= 4 ? What am I actually suppose to do when it gives me f(-1)= 4 and asks for the domain and range.

 

[masters]

When I have f(x)=5-3x and x=-4 and x=2 how should I begin to work this. Also when I'm supposed to find the domain and range from f(-1)= 4 ? What am I actually suppose to do when it gives me f(-1)= 4 and asks for the domain and range.

Hi comprehension2,

The domain of the function is the set of values that can be taken on by the independent variable x so that the expression in the function is real. The range is the set of values assigned to the dependent variable y based on the domain values.

In f(-1)=4, the domain is -1 and the range is 4.

In f(x)=5-3x, the domain is all real numbers and the range is all real numbers. This means that there are no restrictions in the function that would exclude any value of x. And the range is dependent on that, so it doesn't have any restrictions, either.

I'm not really sure what you're asking in the first sentence. Do you want to determine the range if x = -4 and x = 2. If so, then substitute those values into the f(x) function and determine the range.