Domain/Range/Value?????????

Question

Please help me in figuring this out.


Using the domain values {-1, 0, 4}, find the range values for relation y=2x-10.

Range={-11, -10, -6}
Range={12, -10, 2}
Range={-12, -10, -2}
None of the above

Answer 1

Range={-12, -10, -2}

Put the values of x from the domain and get the values of y as range.

Answer 2

Domain: values that a variable can take in a function (input)
Range: values that can be returned by the function (output)

y = 2x - 10

x is the variable. x can take on values of the domain.
y is the function. y will determine values of the range.

There are no natural restrictions on the domain. A function like a square root does have a natural restriction in real number: you can't take the square root of a negative number.

Here, you are given a domain: a set of three values. You try each one and find out the set of possible values.

If you put -1 in the place of x (the variable), the value of the function (y) is 2*(-1)-10 = -12.

We have eliminated the first choice (it does not contain -12 in the range).

If you put +4 in the place of x, the function returns 2*(4) - 10 = 8 - 10 = -2

We have just eliminated the second choice (it does not contain -2 in the range).

I'll let you try x= 0 to see if you confirm or eliminate the third choice.