Question

For which x values does the graph of y=4^x cross the x-axis?
a. none
b. negative values of x
c. x values less that 1
d. positive values of x

Answer 1

If the graph of this function crossed the x axis, then for some x,

4^x = 0.

Is there such a number x?

Answer 2

0?, so none?

Answer 3

Well, 4^0 = 1.

In fact, there is no such x. Hence y = 4^x is never zero. Hence ...

Answer 4

if by none you mean answer A, you are correct

Answer 5

yes, thank you for the explanation

Answer 6

the range of the exponential function is y>0, i.e., strictly greater than zero