- #1
Mdhiggenz
- 327
- 1
Homework Statement
So I took my calc 3 exam today and had this question
true or false
magnitude ( v+v) = 2*magnitude( v)
I put true.
Thoughts?
Exam question t/f
- Thread starter Mdhiggenz
- Start date
So I took my calc 3 exam today and had this question
true or false
magnitude ( v+v) = 2*magnitude( v)
I put true.
Thoughts?
Answers and Replies
- #2
- 9,568
- 774
You got it correct. Were you just guessing?
- #3
Mdhiggenz
- 327
- 1
No I did a problem where I had to solve for K in the magnitude give the value of v. Pretty much I took k from the magnitude and solved for it. So I was hoping the same thing applied here.
- #4
skiller
- 237
- 5
Really? I don't see how this is correct.
- #5
- 9,568
- 774
If ##\vec v = \langle a,b,c\rangle## what do you get for ##|\vec v|## and ##|2\vec v|##?
- #6
skiller
- 237
- 5
Sorry, of course it's correct.
I was having a senile moment when I was imagining the two vectors weren't the same! D'oh!
- #7
- 9,568
- 774
Sorry, of course it's correct.
I was having a senile moment when I was imagining the two vectors weren't the same! D'oh!
Don't feel to bad about that. My first reaction was the same because I was expecting the question to read u+v since, in my opinion, that would have been a better question. Only after I started my reply did I realize the OP had v+v.
- #8
- #9
skiller
- 237
- 5
Did the same thing here.
I obviously need to learn to read twice before posting. Something which you two are obviously better at than me!
- #10
Mark44
Mentor
- 36,698
- 8,687
If v happened to be perpendicular to itself, the original statement wouldn't be true.:tongue:
(The zero vector not included, of course.)
(The zero vector not included, of course.)
- #11
skiller
- 237
- 5
Now you've lost me!
- #12
Mark44
Mentor
- 36,698
- 8,687
Math humor...
A nonzero vector can't be perpendicular to itself.
A nonzero vector can't be perpendicular to itself.
- #13
- 9,568
- 774
What if it's bent?