How do you find the angel between u=5i-4j, v=2i+j? Precalculus Dot Product of Vectors Angle between Vectors 1 Answer Narad T. Oct 15, 2016 Use the dot product definition #u.v=∥u∥∥v∥cos(u,v)# #cos(u,v)=(u.v)/(∥u∥∥v∥)# #u.v=5*2-4*1=6# #∥u∥=sqrt(5^2+4^2)=sqrt41# #∥v∥=sqrt(2^2+1^2)=sqrt5# #cos(u,v)=6/(sqrt41.sqrt5)=0.6266# #(u,v)=0.894 rd# Answer link Related questions How do I calculate the angle between two vectors? How do I find the sine of the angle between two vectors? How do I find the angle between two vectors using the law of cosines? What are common mistakes students make with angles between vectors? How do I find the angle between a vector and the x-axis? What is the dot product of two vectors that are parallel? How do I find out if vectors are parallel? What is the dot product of two vectors that are perpendicular? How do I find the angle between vectors #<3, 0># and #<5, 5>#? Consider the following vectors: v = 3i + 4j, w = 4i + 3j, how do you find the angle between v and w? See all questions in Angle between Vectors Impact of this question 4582 views around the world You can reuse this answer Creative Commons License