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Help Me! I suck with vectors.
Look at the attached pictures for the problem.

Help Me! I suck with vectors. Look at the attached pictures for the problem.-example-1
Help Me! I suck with vectors. Look at the attached pictures for the problem.-example-1
Help Me! I suck with vectors. Look at the attached pictures for the problem.-example-2

1 Answer

1 vote

Multiplying a vector
x by a constant
k gives you a new vector whose components are the same as
x, but scaled by
k:


x=\langle x_1,x_2\rangle\implies x=\langle kx_1,kx_2\rangle

So we have


u=\langle5,-7\rangle\implies-6u=\langle-30,42\rangle


v=\langle-11,3\rangle\implies2v=\langle-22,6\rangle

Vector addition is just a matter of adding the corresponding components together:


x=\langle x_1,x_2\rangle,y=\langle y_1,y_2\rangle\implies x+y=\langle x_1+y_1,x_2+y_2\rangle

Then


2v-6u=\langle-22,6\rangle+\langle-30,42\rangle=\langle-22-30,6+42\rangle


\implies\boxed{2v-6u=\langle-52,48\rangle}


\|x\| denotes the norm/magnitude of the vector
x:


x=\langle x_1,x_2\rangle\implies\|x\|=\sqrt{{x_1}^2+{x_2}^2}

We have


\|2v-6u\|=√((-52)^2+48^2)=4√(313)


\implies\boxed\

User Pschang
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