A problem in Quadratic Equations

In summary, the equation can take the value √5 only if the inputs are coprime and the equation has at least one solution.
  • #1
Wrichik Basu
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Homework Statement



Find the number of solutions of the equation $$\sqrt {x^2}-\sqrt {(x-1)^2} + \sqrt {(x-2)^2}=\sqrt {5}$$
Answer given: 2

Homework Equations



The Attempt at a Solution



Completely clueless as to where to start.
 
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  • #2
Wrichik Basu said:

Homework Statement



Find the number of solutions of the equation $$\sqrt {x^2}-\sqrt {(x-1)^2} + \sqrt {(x-2)^2}=\sqrt {5}$$
Answer given: 2

Homework Equations



The Attempt at a Solution



Completely clueless as to where to start.
What is the square root of the square of a number ? ##\sqrt{a^2} = ?##
 
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  • #3
Wrichik Basu said:

Homework Statement



Find the number of solutions of the equation $$\sqrt {x^2}-\sqrt {(x-1)^2} + \sqrt {(x-2)^2}=\sqrt {5}$$
Answer given: 2

.
Write the equation without square roots and squares. Do you know what is ##\sqrt{3^2}##? and ##\sqrt{(-3)^2}##? And what is ##\sqrt{a^2}## in general?
 
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  • #4
ehild said:
Write the equation without square roots and squares. Do you know what is ##\sqrt{3^2}##? and ##\sqrt{(-3)^2}##? And what is ##\sqrt{a^2}## in general?
##\sqrt{a^2} = |a|##, that much I know. And the others are both 3.
 
  • #5
ehild said:
Write the equation without square roots and squares. Do you know what is ##\sqrt{3^2}##? and ##\sqrt{(-3)^2}##? And what is ##\sqrt{a^2}## in general?
You mean to say that the expression reduces to ## |x|-|x-1|+|x-2|=\sqrt {5}##?

Then I can solve it without problem, just tell if my evaluation is correct.
 
  • #6
Wrichik Basu said:
You mean to say that the expression reduces to ## |x|-|x-1|+|x-2|=\sqrt {5}##?

Then I can solve it without problem, just tell if my evaluation is correct.
Yes, it is correct. Just plot the function, and see, if it can take the value √5, and how many times.
 
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  • #7
ehild said:
Yes, it is correct. Just plot the function, and see, if it can take the value √5, and how many times.
Right, plot on a number line and... I understood. Thank you, sir. :partytime:
 
  • #8
Well, this is the plot

upload_2017-5-22_23-27-0.png
 
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FAQ: A problem in Quadratic Equations

What is a quadratic equation?

A quadratic equation is an algebraic equation of the form ax^2 + bx + c = 0, where a, b, and c are constants and x is a variable. It is called a quadratic equation because the highest power of the variable is 2.

What is the difference between a linear and quadratic equation?

The main difference between a linear and quadratic equation is the highest power of the variable. In a linear equation, the highest power is 1, while in a quadratic equation, the highest power is 2. This means that a quadratic equation can have two solutions, while a linear equation only has one solution.

How do you solve a quadratic equation?

There are several methods for solving a quadratic equation, including factoring, completing the square, and using the quadratic formula. The most commonly used method is the quadratic formula, which is x = (-b ± √(b^2-4ac)) / 2a. This formula can be used to find the two solutions of any quadratic equation.

Can a quadratic equation have complex solutions?

Yes, a quadratic equation can have complex solutions. This means that the solutions involve imaginary numbers, such as √-1. Complex solutions occur when the discriminant (b^2-4ac) is negative, indicating that the solutions are not real numbers.

How are quadratic equations used in real life?

Quadratic equations have many real-life applications, such as in physics, engineering, and finance. They can be used to model the motion of objects, calculate the maximum or minimum value of a function, and solve optimization problems. They are also used in graphing to create parabolas, which can represent various real-world phenomena.

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