Question

The function f(x)= -a^x +4 will never cross the x-axis. True or false??

Answer 1

I think its true

Answer 2

um i agree with @NaomiBell1997

Answer 3

I think it is true, also, it will approach it closely, but never cross

Answer 4

can someone help me with my question

Answer 5

I think I just did.

Answer 6

ali1029 do you know how \(\bf y= x^2\) looks like?

Answer 7

If a > 1, the function can cross the x axis.
y = -a^x +4
To find where it crosses or touches the x axis, set y = 0 and solve for x
0 = -a^x + 4
add a^x to both sides
a^x = 4
take log on both sides
xlog(a) = log(4)
x = log(4) / log(a) is the point where it will cut/touch the x axis for a > 1

Answer 8

if a was positive, would the answer be false?