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PLEASE HELP PLSS

Find the angle between the given vectors to the nearest tenth of a degree.

u = <2, -4>, v = <3, -8>

User Snakebyte
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2 Answers

3 votes

For those who see what the person wrote above, the answer is 6.0*

User Pookieman
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\cos\theta=\frac{\vec{u}\circ\vec{v}}{|\vec{u}|\cdot|\vec{v}|}\\\\\vec{u}= \ \textless \ 2;-4 \ \textgreater \ ;\ \vec{v}= \ \textless \ 3;-8 \ \textgreater \ \\\\\vec{u}\circ\vec{v}=2\cdot3+(-4)\cdot(-8)=6+32=38\\\\|\vec{u}|=√(2^2+(-4)^2)=√(4+16)=√(20)=√(4\cdot5)=\sqrt4\cdot\sqrt5=2\sqrt5\\\\|\vec{v}|=√(3^2+(-8)^2)=√(9+64)=√(73)\\\\|\vec{u}|\cdot|\vec{v}|=2\sqrt5\cdot√(73)=2√(365)\\\\\cos\theta=(38)/(2√(365))\approx0.9945\to\theta\approx6^o\\\\Answer:The\ angle\ between\ \vec{u}\ and\ \vec{v}:\theta\approx6^o.
User Dayum
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