.
Cosine of the angle between the vectors "a" and "b" is equal to the scalar product of the vectors "a" and "b",
divided by the product of their lengths
= .
So, you have: the scalar product is (-2)*6 + 3*2 = -12 + 6 = -6;
|a| = = ;
|b| = = .
Therefore, = = = -0.26312.
So, = arccos(-0.26312) = 1.837 radians. ANSWER
Solved.
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If you want more explanation and/or an entire topic to learn from, look into the lessons
- Introduction to dot-product
- Formula for Dot-product of vectors in a plane via the vectors components
- Dot-product of vectors in a coordinate plane and the angle between two vectors
- Perpendicular vectors in a coordinate plane
- Solved problems on Dot-product of vectors and the angle between two vectors
- Properties of Dot-product of vectors in a coordinate plane
- The formula for the angle between two vectors and the formula for cosines of the difference of two angles
- HOW TO find dot-product of two vectors in a plane
- HOW TO find scalar product of two vectors in a coordinate plane
- HOW TO find the angle between two vectors in a coordinate plane
For the full list of my lessons on dot-product with short annotations see the file OVERVIEW of lessons on Dot-product.
Also, you have this free of charge online textbook in ALGEBRA-II in this site
ALGEBRA-II - YOUR ONLINE TEXTBOOK.
The referred lessons are the part of this online textbook under the topic "Dot-product for vectors in a coordinate plane".
Save the link to this textbook together with its description
Free of charge online textbook in ALGEBRA-II
https://www.algebra.com/algebra/homework/complex/ALGEBRA-II-YOUR-ONLINE-TEXTBOOK.lesson
into your archive and use when it is needed.