Asked by Alex
If 'a' and 'b' are unit vectors that make an angle of 60 degrees with each other, calculate
l 3a - 5b l and l 8a + 3b l
*the 'a' and 'b' have a carat of top of them*
How do i answer this without using components?
l 3a - 5b l and l 8a + 3b l
*the 'a' and 'b' have a carat of top of them*
How do i answer this without using components?
Answers
Answered by
Steve
I guess you could use the law of cosines.
Draw a diagram and you will see that
|3a-5b|^2 = 3^2+5^2-2*3*5*cos120°
do the same for the other
Draw a diagram and you will see that
|3a-5b|^2 = 3^2+5^2-2*3*5*cos120°
do the same for the other