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35 votes
35 votes
100 PTS!! PLEASE HELP! OVER DUE

100 PTS!! PLEASE HELP! OVER DUE-example-1
User Priyan RockZ
by
3.0k points

2 Answers

10 votes
10 votes

Answer:

Explanation:

Look at the component form of each vector.

Note that vector c is <4,4> and vector d is <-2,-2>

If one imagined the line that contained each vector, the line for both would have a slope of 1, because

Since they have the same slope they are parallel, but since they are in opposite directions, we often call them "anti-parallel" (simply meaning parallel, but in opposite directions).

If two vectors are parallel, one vector can be multiplied by a scalar to result in the other vector. This means that there is some number "k", such that , or equivalently, and .

If and , we just need to substitute known values and solve for k:

Double checking that k works for the y-coordinates as well:

?

So,

User Timothy Green
by
2.8k points
22 votes
22 votes

Answer:


-(1)/(2) \vec {c}

Explanation:

Look at the component form of each vector.

Note that vector c is <4,4> and vector d is <-2,-2>

If one imagined the line that contained each vector, the line for both would have a slope of 1, because
(4)/(4)=1=(-2)/(-2)

Since they have the same slope they are parallel, but since they are in opposite directions, we often call them "anti-parallel" (simply meaning parallel, but in opposite directions).

If two vectors are parallel, one vector can be multiplied by a scalar to result in the other vector. This means that there is some number "k", such that
k \vec{c} = \vec {d}, or equivalently,
kc_x=d_x and
kc_y=d_y.

If
kc_x=d_x and
kc_y=d_y, we just need to substitute known values and solve for k:


kc_x=d_x\\k(4)=(-2)\\k=(-2)/(4)\\k=-(1)/(2)

Double checking that k works for the y-coordinates as well:


kc_y=d_y


(-(1)/(2)) (4) ?
(-2)


-2=-2 \text{ } \checkmark

So,
-(1)/(2) \vec {c} = \vec {d}

User Anubis
by
2.7k points