Chapter 5: Problem 6
For the following exercises, write an equation describing the relationship of the given variables. \(y\) varies directly as the square root of \(x\) and when \(x=36, y=24\).
Short Answer
Expert verified
The equation is \( y = 4 \sqrt{x} \).
Step by step solution
01
Understand direct variation
When we say that a variable \( y \) varies directly as the square root of \( x \), it means we can express their relationship using the equation \( y = k \sqrt{x} \), where \( k \) is a constant. Our task is to find the value of the constant \( k \).
02
Substitute known values
We are given that when \( x = 36 \), \( y = 24 \). Substitute these values into the equation \( y = k \sqrt{x} \) to determine \( k \). So, \( 24 = k \sqrt{36} \).
03
Calculate \( \sqrt{x} \)
Find the square root of \( x \). In this case, \( \sqrt{36} = 6 \).
04
Solve for \( k \)
Substitute \( \sqrt{36} = 6 \) into the equation from Step 2: \( 24 = k (6) \). Divide both sides by 6 to solve for \( k \). This gives \( k = \frac{24}{6} = 4 \).
05
Write the final equation
Now that we have \( k \), substitute it back into the equation \( y = k \sqrt{x} \). The relationship between \( y \) and \( x \) is therefore \( y = 4 \sqrt{x} \).
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
The concept of a square root is fundamental in algebra. When we talk about the square root of a number, we're referring to a value that, when multiplied by itself, gives the original number. For example, the square root of 36 is 6 because 6 multiplied by itself (6 × 6) equals 36. This operation helps in simplifying equations and understanding relationships between variables.
- Notion: The square root is represented by the radical symbol (√).
- Use in equations: Solves many algebraic problems by simplifying numbers under the radical.
- Relation to direct variation: Shows how a variable can directly change as another's square root changes.
Constant of Variation
The constant of variation, represented by the symbol \( k \), is a key component in direct variation equations. It serves as the proportionality constant that describes how much one variable changes with respect to a change in another.
- Definition: \( k \) is the multiplier that scales the relationship between variables.
- Role: Determines how steep or shallow this variation is.
- Dependence: On the initial conditions or values given in the problem.
Algebraic Equation
An algebraic equation is a mathematical statement that shows the equality between two expressions. These equations are essential in solving for unknown values and understanding relationships between variables.
- Structure: Composed of variables, constants, and operations such as addition, multiplication, and roots.
- Purpose: To express relationships and solve for unknowns.
- Example: In our exercise, the equation \( y = k \sqrt{x} \) shows the direct relationship between \( y \) and the square root of \( x \).
Solving for k
To find the constant of variation \( k \) in an algebraic equation, like \( y = k \sqrt{x} \), the process involves substituting known values and algebraic manipulation.
- Substitute given values into the equation to replace variables with numbers.
- Calculate necessary components, like square roots, before solving for \( k \).
- Isolate \( k \) by performing inverse operations.