Question

Find the exponential function f(x) = a^x,intersect a point (-2,9)

Answer 1

plug in x=-2 and f(-2) = 9, then solve for 'a'.

Answer 2

but i can not get the answer right

Answer 3

the point (-2,9) is in the form (x,f(x))
if you plug it in \[f(x)=a^x=9=a^{-2}\]
You have to use logarithms to solve for a.
\[a^x=y\]
\[log_a(y)=x\]

Answer 4

a=1/3?

Answer 5

answer is (1/3)^x?

Answer 6

yes