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

[adhiluhur]

Homework Statement

Homework Equations

The Attempt at a Solution

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.

 

[lewando]

What is the distance between M and O?

 

[adhiluhur]

What is the distance between M and O?

By simple Pythagorean theorem you can work it out to l^2 sqrt{2}

 

[lewando]

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
$$l \sqrt{2}$$

 

[adhiluhur]

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.

 

[lewando]

Ahh.. nevermind me, I thought I saw it... standby please.

 

[adhiluhur]

Ahh.. nevermind me, I thought I saw it... standby please.

I think my answer is correct and the computer is wrong.

 

[lewando]

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?

 

[WatermelonPig]

Use more sets of parentheses at the beginning.

 

[adhiluhur]

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.

 

[Hootenanny]

Enlighten me.

What is the magnitude of the vector $\boldsymbol{x} = \boldsymbol{i}+\boldsymbol{j} = [1,1]^\text{T}$?

 

[stallionx]

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 ?