whats the domain of 2x^2+5x-7

Question

i dont know how to answer this problem i need the help

Answer 1

 

The domain of your function will be all real numbers. This is because for any real number you substitute in for x, you will get a defined output.

 

 

Contrast it with the function

 

f(x) = (3x + 1) / (x+3)

 

The domain of this example function is all real number EXCEPT -3, because

 

f(-3) = (3(-3)+1)/ (-3 + 3) = -8/0 ---> Undefined!

 

 

Answer 2

Hi Juan, the domain of the expression, 2x² + 5x - 7, is any number since any value of x will make sense.

 

Questions?

Answer 3

The doman for all polynomial functions of the type y=ax²+bx+c (a not = zero, b and c any real numbers) is automatically all real numbers.

 

This equation is quadratic, and all quadratics model parabolas. The domain for all parabolas is all real numbers.