/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 22 For each function: a. Evaluate... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

For each function: a. Evaluate the given expression. b. Find the domain of the function. c. Find the range. $$ f(x)=-\sqrt{-x} ; \text { find } f(-100) $$

Short Answer

Expert verified
f(-100) = -10; Domain: \((-\infty, 0]\); Range: \((-\infty, 0]\).

Step by step solution

01

Evaluate the Expression

First, substituting \(x = -100\) into the function \(f(x) = -\sqrt{-x}\), we have: \[ f(-100) = -\sqrt{-(-100)} \]}{
02

Simplify the Expression

Now, simplify the expression inside the square root: \(-(-100) = 100\). So, \[ f(-100) = -\sqrt{100} \] \[ f(-100) = -10 \]
03

Determine the Domain of the Function

The domain of a function involving a square root, like \(-\sqrt{-x}\), is determined by setting the expression inside the square root greater than or equal to 0: \(-x \geq 0\) Therefore, \(x \leq 0\). So, the domain of the function is \(x \in (-\infty, 0]\).
04

Determine the Range of the Function

Since \(-\sqrt{-x}\) produces negative values and zero, the range consists of all non-positive numbers. The square root will cover all non-negative real numbers, but due to the negative sign in front of the square root, the range is \((-\infty, 0]\).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Square Root Functions
When we talk about square root functions, we are dealing with functions that involve the square root symbol (√). These functions will produce outputs by extracting the square root of a given input, usually a non-negative number.
In mathematics, we commonly see the square root function written as \(\sqrt{x}\). It simplifies to the value that, when multiplied by itself, gives back the original number \(x\). For example, \(\sqrt{4} = 2\) because \(2 \times 2 = 4\).
However, situations change when the expression involves more complexity, such as negative signs or other operations within the square root. In the context of the problem we are discussing, we have \(-\sqrt{-x}\). This differs from the simple square root of \(x\) by involving a negative input, allowing negative values in a very particular manner.
  • This function, \(-\sqrt{-x}\), accepts non-positive inputs.
  • The negative sign outside the square root affects the output, flipping the sign of the result.
Understanding these nuances is key to working reliably with square root functions in different forms. Feel free to try substituting various numbers to see how it changes the output! Remember always to handle the expression inside the square root carefully to know what values are permissible for input.
Function Evaluation
Function evaluation is a simple but crucial concept in math. It involves replacing a variable within a function with a given number and then simplifying it to find the result.
Consider the function \(f(x) = -\sqrt{-x}\). To find \(f(-100)\), you substitute \(x = -100\) directly into the function.
Here's how it works step-by-step:
  • First, replace \(x\) with \(-100\): \(-\sqrt{-(-100)}\).
  • Then, simplify the term inside the square root: \(-(-100) = 100\).
  • Finally, compute the square root and apply the negative sign: \(-\sqrt{100} = -10\).
Thus, when \(x = -100\), the function evaluates to \(-10\). Function evaluation helps us understand what output we can expect from giving specific inputs. It's useful across many areas of math, including finding particular characteristics like the domain and range of functions.
Negative Numbers in Functions
Negative numbers present interesting challenges and features in mathematical functions. Specifically, in our context with \(-\sqrt{-x}\), understanding how negative numbers affect calculations is essential.
Consider the expression \(-\sqrt{-x}\). Here, two negatives interact:
  • The negative sign inside the square root ensures that \(x\) must be non-positive (zero or less).
  • The negative sign outside the square root then reverses the sign of the output of \(\sqrt{-x}\) after it's been solved.
Negative numbers by themselves imply the opposite of their positive counterparts. However, when employed in mathematical operations like our square root scenario, they enable different solutions and results.
Therefore, working with negative numbers inside functions can dramatically alter what inputs are valid, impacting both the domain and range of the function. It's important always to consider the location of the negative signs in the expression to predict the behavior of the function accurately.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

GENERAL: Boiling Point At higher altitudes, water boils at lower temperatures. This is why at high altitudes foods must be boiled for longer times - the lower boiling point imparts less heat to the food. At an altitude of \(h\) thousand feet above sea level, water boils at a temperature of \(B(h)=-1.8 h+212\) degrees Fahrenheit. Find the altitude at which water boils at 98.6 degrees Fahrenheit. (Your answer will show that at a high enough altitude, water boils at normal body temperature. This is why airplane cabins must be pressurized - at high enough altitudes one's blood would boil.)

\(99-100 .\) BUSINESS: Isoquant Curves An isoquant curve (iso means "same" and quant is short for "quantity") shows the various combinations of labor and capital (the invested value of factory buildings, machinery, and raw materials) a company could use to achieve the same total production level. For a given production level, an isoquant curve can be written in the form \(K=a L^{b}\) where \(K\) is the amount of capital, \(L\) is the amount of labor, and \(a\) and \(b\) are constants. For each isoquant curve, find the value of \(K\) corresponding to the given value of \(L\). $$ K=3000 L^{-1 / 2} \text { and } L=225 $$

If an object is thrown upward so that its height (in feet) above the ground \(t\) seconds after it is thrown is given by the function \(h(t)\) below, find when the object hits the ground. That is, find the positive value of \(t\) such that \(h(t)=0 .\) Give the answer correct to two decimal places. [Hint: Enter the function in terms of \(x\) rather than \(t .\) Use the ZERO operation, or TRACE and ZOOM IN, or similar operations. $$ h(t)=-16 t^{2}+45 t+5 $$

BUSINESS: Semiconductor Sales The following table shows worldwide sales for semiconductors used in cell phones and laptop computers for recent years. \begin{tabular}{lccc} \hline Year & 2011 & 2012 & 2013 \\ \hline Sales (billions \$) & 80.2 & 87.1 & 93.6 \\ \hline \end{tabular} a. Number the data columns with \(x\) -values \(1-3\) (so that \(x\) stands for years since 2010 ), use power regression to fit a power curve to the data, and state the regression formula. [Hint: See Example 7.] b. Use the regression formula to predict sales in \(2020 .\) [Hint: What \(x\) -value corresponds to \(2020 ?]\)

For the quadratic function \(f(x)=a x^{2}+b x+c,\) what condition on one of the coefficients will guarantee that the function has a highest value? A lowest value?

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.