Posted by Hannah on Sunday, March 28, 2010 at 5:08pm.
\vec b\cdot \vec c = \Vert \vec b\Vert\Vert\vec c\Vert\cos \theta
The law of cosines in vector form:
b dot c= abs b * abs c *CosA
(3i+j)dot(2i-j)=sqrt(10)*sqrt(5) CosA
CosA=5/5sqrt2= .707
solve for A
Related Questions
pre-Cal(Please help) - Use the law of cosines to find the angle Q between the ...
Math - Use the law of cosines to find the angle Q between the given vectors. v...
math help people lik really desperate!! - ok i have to divide complex numbers: ...
check my work please! - ok i have to divide complex numbers: question is: 1-2i+i...
vectors - Given the vectors v=-2i+5j and w=3i+4i, determine (do I just plug what...
Help on Vectors & Geometry - (a) Given that A= 3i - j + 2k and B=2i + 3j - k...
Algebra - I have to rationalize the denominator of 2+3i/1+2i. I multiplyed this ...
algebra - Find the angles between the following pairs of vectors (1)3i+2j-6k,4i-...
algebra - Find the angles between the following pairs of vectors (1)3i+2j-6k,4i-...
math - Please help me. I can't seem to get the answer of 165 degrees. Find ...
For Further Reading
