Question

Which exponential function goes through the points (1, 8) and (4, 64)?

f(x) = 4(2)^x

f(x) = 2(4)^x

f(x) = 4(2)^(-x)

f(x) = 2(4)^(-x)

Answer 1

Plug in the x and y value for (1, 8) into the first function, check if it's true (both sides are equal). If it's true, do the same with (4,64), check if it's true.

You can already eliminate the 3rd and 4th options - the -x means they can't possibly work. The -x means it'd be a decreasing function, so y will always get smaller and smaller as x increases (look at the points (1, 8) and (4, 64) - y got larger when x got larger)

Answer 2

A?