### Home > A2C > Chapter 3 > Lesson 3.2.1 > Problem 3-95

3-95.

Find a possible exponential function in *y* = *a · b ^{x} *form that represents each situation described below. Homework Help ✎

Has an initial value of 2 and passes through the point (3, 128).

Passes through the points (0, 4) and (2, 1).

Since it has an initial value of 2, the value of *a* is 2.

Substitute this into the general equation: *y* = *ab ^{x}*

Substitute the values 3 and 128 for *x* and *y*, respectively, then solve for *b*.

Create two equations substituting the values of the ordered pairs for *x* and *y* into the equation *y* = *ab ^{x}*.

Solve the system of equations for *a* and *b*.

Be sure you use your results for *a* and *b* to write the equation.