# Vectors

• November 12th 2006, 02:28 AM
classicstrings
Vectors
Vectors a and b are such that the magnitude of a = magnitude of b and the angle between a and b is 40 degress. The angle between vectors a and a + b is?

Thanks for the help!
• November 12th 2006, 02:40 AM
earboth
Quote:

Originally Posted by classicstrings
Vectors a and b are such that the magnitude of a = magnitude of b and the angle between a and b is 40 degress. The angle between vectors a and a + b is?

Thanks for the help!

Hello, classicstrings,

do the addition of vectors geometrically. Because $\|{\vec{a}}=\|{\vec{b}}$ you'll get a rhombus. Thus the vector $\vec{a}+\vec{b}$ bisect the angle. So the value of the angle you are looking for is 20°.

EB
• November 12th 2006, 03:08 AM
classicstrings
dankeschön! My german exam is tommorrow :D, then maths on Wednesday, then chinese on thursday!