1. For each of the following functions, find the domain and range, and sketch the graph of:
A$f(x) = x^{1/6}$
B$h(x) = x^{1/7}$


  1. Find the absolute value of each of the following numbers:
A$-2/5$
B$1/7$
C$-5/4$

Verified Answer :

  • The function \(f(x) = x^{1/6}\) has domain \([0, \infty)\) and range \([0, \infty)\), with a graph starting at \((0,0)\) and increasing.
  • The function \(h(x) = x^{1/7}\) has domain \((-\infty, \infty)\) and range \((-\infty, \infty)\), with a graph symmetric about the origin passing through \((-1,-1), (0,0),\) and \((1,1)\).
  • Absolute values are computed as: \(|-\frac{2}{5}| = \frac{2}{5}\), \(|\frac{1}{7}| = \frac{1}{7}\), and \(|-\frac{5}{4}| = \frac{5}{4}\).
  • Final answers: Domain/Range of \(f(x)\): \(\boxed{[0, \infty), [0, \infty)}\); Domain/Range of \(h(x)\): \(\boxed{(-\infty, \infty), (-\infty, \infty)}\); Absolute values: \(\boxed{\frac{2}{5}, \frac{1}{7}, \frac{5}{4}}\).

Explanation

  1. Analysis of f(x) = x^{1/6}

For the function \(f(x) = x^{1/6} = \sqrt[6]{x}\), we note that it involves an even root. An even root is only defined for non-negative real numbers because the power of an even number is always non-negative. Therefore, the domain of \(f(x)\) is \(x \geq 0\), or in interval notation, \([0, \infty)\). As \(x\) increases from 0 to \(\infty\), \(\sqrt[6]{x}\) also increases from 0 to \(\infty\). Thus, the range of \(f(x)\) is \(f(x) \geq 0\), or \([0, \infty)\). The graph starts at the origin \((0,0)\) and passes through points like \((1,1)\) and \((64,2)\), displaying a curve that increases at a decreasing rate.

  1. Analysis of h(x) = x^{1/7}

For the function \(h(x) = x^{1/7} = \sqrt[7]{x}\), we observe that it involves an odd root. Odd roots are well-defined for all real numbers because a negative number raised to an odd power remains negative. Therefore, the domain of \(h(x)\) is all real numbers, denoted as \((-\infty, \infty)\). Similarly, the range of \(h(x)\) extends over all real numbers as \(x\) varies from \(-\infty\) to \(\infty\). The graph passes through the origin \((0,0)\), \((1,1)\), and \((-1,-1)\). It also passes through \((128,2)\) and \((-128,-2)\), creating a shape that is symmetric with respect to the origin and increases throughout its entire domain.

  1. Calculating Absolute Values

The absolute value of a number \(a\), denoted as \(|a|\), represents its distance from 0 on the number line. It is defined as \(|a| = a\) if \(a \geq 0\) and \(|a| = -a\) if \(a < 0\).

AFor \(-\frac{2}{5}\): Since \(-\frac{2}{5} < 0\), its absolute value is \(-(-\frac{2}{5}) = \frac{2}{5}\).
BFor \(\frac{1}{7}\): Since \(\frac{1}{7} > 0\), its absolute value is \(\frac{1}{7}\).
CFor \(-\frac{5}{4}\): Since \(-\frac{5}{4} < 0\), its absolute value is \(-(-\frac{5}{4}) = \frac{5}{4}\).

Examples

In everyday life, functions like square roots and cube roots are used in geometry to relate areas and volumes to side lengths. For example, if you know the volume of a cube is \(V\), its side length is found by calculating \(V^{1/3}\). Similarly, absolute values are essential in situations where direction doesn't matter, such as measuring the distance between two points on a map or calculating the margin of error in manufacturing or data collection, ensuring that variations are always treated as positive magnitudes.