Exercise 21 Page 278

Let's analyze the given function. f(x)= 2( 0.5)^x We see that the initial value of the function is 2 and the constant multiplier is 0.5. Therefore, it intercepts the y-axis at (0, 2). Since 0< 0.5<1, it is a decreasing function. The function f matches graph C.

Extra

Graphing Exponential Functions

When we draw an exponential function y=ab^x, the values of a and b change the shape of the graph. The graphs below show possible graphs of exponential functions.