1.1 Functions

1.

(a) $f(1) = 1$ (b) $f(1) = 13$ (c) $f(1) = 2$

2.

(a) Domain(f) $= (-\infty, \infty)$ Range(f) $= [-1, \infty)$．

(b) Domain(f) $= [1, \infty)$ Range(f) $= [0, \infty)$．

(c) Domain(f) $= (-\infty, \infty)$ Range(f) $= [0, 1]$．

3.

(a) The graph of $y = f(x) + c$ is a parallel shift of the graph of $y = f(x)$ by $c$ into the positive $y$-axis direction．

(b) The graph of $y = f(x - a)$ is a parallel shift of the graph of $y = f(x)$ by $a$ into the positive $x$-axis direction．

4.

(a) $${(f \circ g)(x) = 2x^{2} + 5}$$ $${g(f(x)) = (2x+5)^{2}}$$ (b) $(f \circ g)(x) = x$ $g(f(x)) = x$

(c) $${(f \circ g)(x) = \frac{x^{4}}{1 + x^{2}}}$$ $${g(f(x)) = x^{2}(x+1)^{2}}$$

5.

(a) $${f^{-1}(x) = \frac{x+4}{7}}$$ (b) $${y = \sqrt[3]{x-2} - 1}$$ (c) is not one-to-one．

6.

(a) odd function (b) odd function