# Homework Help: Subtracting 3 Vectors

1. Nov 5, 2009

### kateg4

If A= 60.0 and theda = 56.5 degrees
of this graph
http://www.flickr.com/photos/44447874@N08/4079278252/ [Broken]

can you help me find C - A - B?
magnitude and direction (counterclockwise from the +x axis is positive)

Also how do I find 2A - 3B + 2C?

Thank you

Last edited by a moderator: May 4, 2017
2. Nov 5, 2009

### Andrew Mason

Vector subtraction A = C-B can be remembered this way: Ask yourself: what vector A added to B results in C? This is equivalent to switching the head and tail in B (ie multiplying it by -1) and adding it to C.

C - A - B = C + (-A) + (-B)

To add vectors simply add their respective x components to get the x component of the resultant and add the y components to get the y component of the resultant.

So add the x component of C to -1* the x component of A and add -1* the x component of B. Then to the y component of C add -1* the y component of A + -1* y component of B.

AM

Last edited by a moderator: Apr 24, 2017