Question

Find the y=ab^x form of these two points (-2,20) (0,4)

Answer 1

The values that would satisfy this equation are a = 4 and b =
`\sqrt{(1)/(5)}`.

In order to solve this, we'll start by plugging in the second ordered pair into the base equation.

y = ab^x

4 = ab^0 ----> any number raised to the 0 equals 1.

4 = a(1)

4 = a

Now that we know a, we can use the first ordered pair and the a value to solve for b.

y = ab^x

20 = 4b^-2

20 =
`(4)/(b^(2))`

b^2 = 4/20

b^2 = 1/5

b =
`\sqrt{(1)/(5)}`