ive got two vectors and i need to find the angle between them.(adsbygoogle = window.adsbygoogle || []).push({});

AB = -1.95i + 2.4j +.3k

AC = 2.4j+1.8k

i looked up the answer and found it to be 46.8 deg.

i used the equation (AB)(AC) cos theta = ACxABx +ACyABy + ACzABz

the dot product is 6.84. but the equation ends up like this

cos theta = (ACxABx +ACyABy + ACzABz)/(AB)(AC)

this is a dot product on top and on bottom right? i dont quite understand how this works. according to the answer, ABAC should be around 10.

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# Homework Help: Finding angle

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