Which of the following functions has a range of all real numbers?
A. y= -7x + 2
B. y= 4x^2 - 1
C. y= -3x^2 + 5
D. y= 6 (2^x)

Question

Which of the following functions has a range of all real numbers?
A. y= -7x + 2
B. y= 4x^2 - 1
C. y= -3x^2 + 5
D. y= 6 (2^x)

mathmale · Answer

First:  what does "range" mean in this context?

clamin · Answer

The subtraction of smalles and largest number

clamin · Answer

@mathmale

greatlife44 · Answer

Range means the list of all possible y values.

clamin · Answer

Is it C?? @greatlife44

greatlife44 · Answer

The only function that has a range of all real numbers is A. 

$$\mathbb{R} , all~real~numbers$$

because you can get any y value that's from 

$$(-\infty, \infty)$$

welshfella · Answer

yes

note that x^2  cannot be negative for real values of x
so the last 3 options  range is not all real numbers