What is the angle theta between vectors

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SUMMARY

The angle theta between vectors A and B, where A = (4, -3) and B = (-2, 5), is calculated using the formula arccos((A · B) / (|A||B|)). The dot product A · B is computed as -23, and the magnitudes |A| and |B| are found to be approximately 5.0 and 5.39, respectively. The correct calculation yields an angle of approximately 130.81 degrees after resolving initial errors in magnitude calculations.

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  • Familiarity with trigonometric functions, particularly arccosine
  • Basic calculator usage for trigonometric calculations
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Homework Statement


What is the angle theta between vectors vec A and vec B if vec A = 4 -3 and
vec B = -2 + 5?


Homework Equations


arccos((a dot b)/(|a||b|))


The Attempt at a Solution



4*-2+-3*5=-23
sqrt(4^2+-3^2)*sqrt(-2^2+5^2)=10.39

arc
not sure what i am doing wrong but that's the equation i found online and i keep getting undefined when i plug it into my calculator
 
Last edited:
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Show what you plugged in.
 
edited the question, but sorry i realized my error, had a mistake in the magnitudes, got the problem right
 

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