Section 1.4 – Functions
- The definition of a function
- Terminology for functions including domain, range, independent variable, and dependent variable
- Function notation
- Evaluating functions
- Piecewise functions
- Finding the domain of a function
Exercises
Directions: You should try to solve each problem first, and then click "Reveal Answer" to check your answer. You can click "Watch Video" if you need help with a problem.
1. Determine whether each equation represents \(y\) as a function of \(x\)
- \(y-1=4x\)
- \(x=|2y-1|\)
- \(2x^3+y^2=4\)
- \(y^3-4x=6\)
- Yes
- No
- No
- Yes
2. Consider the function \[h(x)=\left\{ \begin{array}{cc}-2x+4 & \textrm{, if } x \leq -1 \\(x-2)^2 & \textrm{, if } x >-1\\ \end{array} \right. \] Find \(h(-2)\), \(h(-1)\), and \(h(2).\)
\(h(-2)=8\)
\(h(-1)=6\)
\(h(2)=0\)
\(h(-1)=6\)
\(h(2)=0\)
3. Find the domain of the following functions.
- \(f(x)=-3x^2+5\)
- \(g(x)=\sqrt{4-3x}\)
- \(p(x)=\cfrac{x-1}{\sqrt{x+4}}\)
- \(q(x)=\sqrt[3]{4-3x}\)
- D: \( (-\infty, \infty)\)
- D: \(\left(-\infty, \dfrac{4}{3}\right]\)
- D: \((-4, \infty)\)
- D: \((-\infty, \infty)\)
4. Find the domain of the following expressions.
- \(\displaystyle \frac{x^2-5x+6}{x^2+2x-8}\)
- \(\displaystyle \frac{1}{\sqrt{x-7}}\)
- Domain: \((-\infty,-4)\cup(-4,2)\cup(2,\infty)\)
- Domain: \((7,\infty)\)