v = (4,2,−1), w = (8,4,−2) Find the angle θ between the vectors v and w
asked Nov 24, 2016 in Other Math Topics by Elise

Your answer

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:

To avoid this verification in future, please log in or register.

1 Answer

Best answer

Magnitude of v=√(4^2+2^2+(-1)^2)=√21; magnitude of w=√84=2√21.

Dot product of v and w=4*8+2*4+(-1)(-2)=42.

The cosine of the angle between them is dot product/product of magnitudes=42/42=1, so the angle between them is zero (they are parallel).

answered Nov 24, 2016 by Rod Top Rated User (486,860 points)
Welcome to MathHomeworkAnswers.org, where students, teachers and math enthusiasts can ask and answer any math question. Get help and answers to any math problem including algebra, trigonometry, geometry, calculus, trigonometry, fractions, solving expression, simplifying expressions and more. Get answers to math questions. Help is always 100% free!
79,816 questions
83,632 answers
66,552 users