How do I solve this problem? What are the steps?

Find a possible exponential function in y=a(b^x) form that represents each situation described below. Your answer should look like y=a(b)^x. Has an initial value of 2 and passes through the point (3,128)

1 Answer
Feb 3, 2018

#y=2(4)^x#

Explanation:

The equation #y = ab^x# describes an exponential function, where #a# is the initial value and #b# is the rate of growth or decay.

We're told that the initial value is #2#, so #a=2#.

#y=2(b)^x#

We are also given the point #(3,128)#. Substitute #3# for #x# and #128# for #y#.

#128=2(b)^3#

Now, solve for #b#.

#128=2(b)^3#
#64=b^3#
#b = root(3) 64#
#b=4#

Thus, the equation is #y=2(4)^x#.