2 vectors. 1st one is 6 meters. The other one has is 4 meters. By adding them together I want a module of 3 meters. What should the angle between those modules be? The answer is 153 degrees but I have no idea how to get to that answer. Thank you!

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Answer 1 · 2018-02-12T10:14:54

$please look at the fallowing details.$ $"please look at the fallowing details."$

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$You can solve it using cosine's theorem.$ $"You can solve it using Cosine's theorem."$

$3^{2} = 6^{2} + 4^{2} + 2 \cdot 6 \cdot 4 \cdot cos θ$ $3^2=6^2+4^2+2*6*4*cos theta$

$9 = 36 + 16 + 48 \cdot cos θ$ $9=36+16+48*cos theta$

$9 = 52 + 48 \cdot cos θ$ $9=52+48*cos theta$

$9 - 52 = 48 \cdot cos θ$ $9-52=48*cos theta$

$- 43 = 48 \cdot cos θ$ $-43=48*cos theta$

$cos θ = - \frac{43}{48}$ $cos theta=-43/48$

$θ = 153.62 d e g$ $theta=153.62" " deg$

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