How do you find the domain of y= x^2-2?

2 Answers
Jacobi J.
Jun 1, 2018

x in RR

Explanation:

x^2-2 is a polynomial, which is defined for all real numbers.

This isn't something mysterious and earth-moving about polynomials, but any number, we can square it, and take it to whatever power for that matter and get a result. And we can subtract 2 from everything. Thus

x inRR

Hope this helps!

Bill Jorgensen
Jun 1, 2018

Domain: {x|x " is " RR} or (-oo, oo) in interval notation.

Range: {y|y >=-2) or [-2, oo)

Explanation:

This function is a quadratic ax^2+bx+c and all quadratics are parabolas their domain is not restricted and is all real numbers:

Domain: {x|x " is " RR} or (-oo, oo) in interval notation.

The range is more interesting as it is shifted down 2 from the parent function:

Range: {y|y >=-2) or [-2, oo)

graph{x^2 -2 [-10, 10, -5, 5]}

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