Newbie Physics Help: Vector Addition & Subtraction

[I am a Newbie]

First, let me say I am new to the forums and new to physics, so if I do something wrong I apologize.

Homework Statement

Consider the 2 vectors
A=4i -3j and B = -1i - 5j

a) Calculate A +B
b) Calculate A-B
c) Calculate |A+B|
d) Calculate |A-B|

The Attempt at a Solution

I easily determined a and b, however c and d are giving me dificulty since I don't exactly know how the absolute value affects the vectors. Any help would be much appreciated - Newb

 

[BlackWyvern]

It means that you turn the vectors into positive values and add or subtract the value of the magnitude stick, which I can't remember the name of.

 

[BlackWyvern]

I was wrong. I didn't check the notation properly. c and d are finding the absolute value of the difference between the vectors. So just subtract / add them normally, and find the hypotenuse of the resultant triangle.

 

[G01]

In this case, the bars mean the length of the vector inside. So for c), the problem is asking for the length of the vector that is the vector sum of A and B. For b), the problem is asking for the length of the vector that is the vector difference of A and B.

Does this help?

 

[I am a Newbie]

Still confused..lol,
a) 3i + -8j
b) 5i +2j
That part I get
is this how to do it?(just like you would use a normal abs value?)
c) |4i+-1i|=|3i| and |-3j+-5j|=|-8j|= 8j
making the FINAL answer 3i+8j
and if that is correct is
d) |4i--1i|=|5i| and |-3j--5j|=|2j|
making that FINAL answer 5i+2j

is this right?

 

[Cephalopoda]

C and D are asking for the resultant magnitude of the vectors, so that means that you take those x and y components, and then calculate the hypotenuse of the triangle that they form. Pythagorean theorem, just do this ((I + I)^2 + (J + J)^2)^(1/2) that that is the answer to C. Magnitude is a scalar, while all of the components are vectors.