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anonymous

  • one year ago

If v1 = (2,4) and v2 = (-1,5), then v1 * v2 is equal to which of the following? A. 22 B. 18 C. (8,-5) D. (-2,20)

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  1. anonymous
    • one year ago
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    I am confused on whether or not I put my answer in parentheses or not. So it would be either B or D.

  2. Elsa213
    • one year ago
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    D. (-2,20)* >.>

  3. anonymous
    • one year ago
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    Would we leave them in the parentese or add the vectors together?

  4. TheSmartOne
    • one year ago
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    Cross product of verctors, right?

  5. anonymous
    • one year ago
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    It doesn't specify but that's what I am assuming.

  6. TheSmartOne
    • one year ago
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    Have they given you a figure or something?

  7. anonymous
    • one year ago
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    Nope, just coordinates.

  8. dan815
    • one year ago
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    pretty sure then want dot product because none of those is cross

  9. anonymous
    • one year ago
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    Here's what I found. I think the answer would be 18... There is yet another operation associated with vectors. Given two vectors v1 = (x1,y1) and v2 = (x2,y2), the dot product of v1 and v2, written , is the scalar: x1x2 + y1y2. In other words, the dot product is obtained by multiplying corresponding coordinates of the two vectors and then adding the results.

  10. anonymous
    • one year ago
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    So -2 + 20 = 18?

  11. dan815
    • one year ago
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    yes that is correct

  12. dan815
    • one year ago
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    for future ref, the cross product of 2 vectors will result in a vector that ins the direction that is perpendicular to both of the vectors in this case, the 2 vectors are in a plane <X,y> so the cross will exist completely in the Z direction <0,0,Z>

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