Chapter 4 - Exponential Functions - 4.3 Graphs of Exponential Functions - Exercises and Problems for Section 4.3 - Exercises and Problems - Page 162: 22

a) $y=a 2^x$ b) $y=2 a^x$

a) The graphs are all increasing and become steeper as the value of $a$ increases. See the graphs below. b) All of the graphs are concave up. The graphs are increasing for $a>1$ as in the cases for $a= 2, 3, 4$ and are decreasing for $0< a< 1$ as in the cases of $a= 0.25, 0.5, 0.75$. The graph is constant for $a= 1$ as expected.