How Do You Calculate the Magnitude of a Vector in the Form Constant * (i + j)?

AI Thread Summary
To calculate the magnitude of a vector in the form Constant * (i + j), one must first recognize that the vector can be expressed as [Constant, Constant]. The magnitude can then be determined using the formula, which involves taking the square root of the sum of the squares of the coefficients. For the vector i + j, this results in a magnitude of √2. The discussion highlights the importance of correctly applying the Pythagorean theorem and clarifying the interpretation of the coefficients involved. Understanding these principles is crucial for accurately determining vector magnitudes.
adhiluhur
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Homework Statement


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Homework Equations


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The Attempt at a Solution


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But as you can see, when I typed the answer on the answer column, the computer marked it as wrong. Please point out my mistake in 24 hours. Thank you.
 
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What is the distance between M and O?
 
lewando said:
What is the distance between M and O?

By simple Pythagorean theorem you can work it out to l^2 sqrt{2}
 
adhiluhur said:
By simple Pythagorean theorem you can work it out to l^2 sqrt{2}
I get something different. Since the clock is ticking, how about
l \sqrt{2}
 
lewando said:
I get something different. Since the clock is ticking, how about
l \sqrt{2}

I was writing the distance squared. So basically our answer for that is same.
 
Ahh.. nevermind me, I thought I saw it... standby please.
 
lewando said:
Ahh.. nevermind me, I thought I saw it... standby please.

I think my answer is correct and the computer is wrong.
 
How about your last step? The answer you gave was the common coefficient of i and j. But to get the magnitude should you not take the root of sum of the squares of these coefficients?
 
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Use more sets of parentheses at the beginning.
 
  • #10
lewando said:
How about your last step? The answer you gave was the common coefficient of i and j. But to get the magnitude should you not take the root of sum of the squares of these coefficients?

Enlighten me.
 
  • #11
adhiluhur said:
Enlighten me.
What is the magnitude of the vector \boldsymbol{x} = \boldsymbol{i}+\boldsymbol{j} = [1,1]^\text{T}?
 
  • #12
When something is in the form Constant * ( i + j ) and you would like to find the magnitude of that

use abs ( Constant * ( i+j) ) = Abs(Constant ) * Abs(i+j)

what is Abs ( i + j ) ?

How would you interpret it ?
 
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