The formula of angle between two lines in space is:(adsbygoogle = window.adsbygoogle || []).push({});

[tex]\vec{a}=(a_1,a_2,a_3)[/tex] ; [tex]\vec{b}=(b_1,b_2,b_3)[/tex]

[tex]cos\alpha=\frac{|\vec{a} \vec{b}|}{|\vec{a}||\vec{b}|}[/tex]

or out from there:

[tex]cos\alpha=\frac{|a_1b_1+a_2b_2+a_3b_3|}{\sqrt{a_1^2+a_2^2+a_3^2}\sqrt{b_1^2+b_2^2+b_3^2}}[/tex]

Why it is [itex]|\vec{a}\vec{b}|[/itex]? Why not [itex]\vec{a} \vec{b}[/itex]?

Scalar product of two vectors is [tex]\vec{a}\vec{b}=|\vec{a}||\vec{b}|cos(\vec{a},\vec{b})[/tex]

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Angle between two lines in space

Loading...

Similar Threads for Angle between lines |
---|

I Difference between R^n and other vector spaces |

I What is difference between transformations and automorphisms |

I Nice intro to connections between algebra and geometry |

**Physics Forums | Science Articles, Homework Help, Discussion**