Question

find the domain and range
f(x)=2x^2+2

Answer 1

The domain is all possible values of x you can put into that equation. Can you plug in 0 for x? Yeah, because it's not in the denominator, since you can't divide by 0. Can you plug in a negative number for x? Yes, because you're not taking the square root of x, since you can't have the square root of a negative number. So you can do anything here, negative to positive infinity.

What about the range? That's all possible y-values you can have. Well, since you see that x is squared, if you plug in a negative x you're always going to get a positive number, so you need to plug in the smallest possible non-negative number to see what your range is, and you can see that's 0, so your range is from 2 to infinity.