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please PLEASE help me!!! Write an expression that can be used to produce vector r from vectors p and q. Explain how you determined that expression

please PLEASE help me!!! Write an expression that can be used to produce vector r-example-1
User JVGD
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1 Answer

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Answer:

r = p - q

Explanation:

Write the two given vectors using i and j components.

i = unit vector in x direction

j = unit vector in y direction

p = -i - 3j

q = 3i - 4j

Now how can you combine these two vectors and get r when

r = -4i + j?

Adding p and q gives this:

p + q = -i - 3j + 3i - 4j = 2i - 7j

That is not r, so the addition of the vectors p and q does not work.

How about subtraction?

Start with -i from p and subtract 3i from q. You do get -4i which is the x-component of r.

Then start with -3j from p and subtract -4j from q. You get -3j - (-4j) = -3j + 4j = j which is the y-component of r.

That subtraction works.

p - q = -i - 3j - (3i - 4j) = -i - 3j - 3i + 4j = -4i + j which is exactly what r is.

Answer: r = p - q

User Shabeeralimsn
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