# Calculating the angle of two vectors 3d?

If , A=3i-2j+3k and B=-2i+4j+2k, Is there a formula im not knowing about.My physics highschool teacher had this as a bonus question.

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- VamanLv 71 month ago
The angle cos theta= A dot B/(magnitude A * magnitude B). This is the standard formula.

A dot B=-6-8+6= -8 magnitude A = sqrt( 9+4+9)=sqrt 22, magnitude B= sqrt (4+16+4) =sqrt 24

The angle cos theta= -8/sqrt(22)/sqrt 24=-0.348, theta=110,36 degrees,

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