Graphing an Exponential Function with a Base Greater Than 1
a) Graph y = 2^x.
b) Determine the domain and range of the function.
a) Substitute values for x and find the corresponding values of y. The graph is shown in Fig. 6.49 on page 380.
y = 2^x
x = -3, y = 2^{-3} = \frac{1}{2³} = \frac{1}{8}
x = -2, y = 2^{-2} = \frac{1}{2²} = \frac{1}{4}
x = -1, y = 2^{-1} = \frac{1}{2¹} = \frac{1}{2}
x = 0, y = 2^0 = 1
x = 1, y = 2¹ = 2
x = 2, y = 2² = 4
x = 3, y = 2³ = 8
b) The domain is all real numbers, \mathbb{R}. The range is y > 0. Note that y can never have a value of 0.
y | x |
\frac{1}{8} | -3 |
\frac{1}{4} | -2 |
\frac{1}{2} | -1 |
1 | 0 |
2 | 1 |
4 | 2 |
8 | 3 |