Here are the graphs of 5 exponential functions The parameter

Here are the graphs of 5 exponential functions. The parameters of the functions are shown.

Answer the following questions about the function parameters. Give a reason for your answer.

1 Which function has a negative parameter?

2 There are two pairs of functions that have the same initial value. Name the functions and explain how you know they have the same initial value.

3 Which function has a base that is less than 1?

Solution

1) the graph with exponential decay with increasing x is the one with -ve parameter

y4 = a4b4^x

2) functions that have the same initial value. :

black graph , red graph cross through same point on y axis

blue graph , green graph cross through same point on y axis

3) Graph purpule y5 = a5b5^x has a base that is less than 1