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anonymous

  • one year ago

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  1. anonymous
    • one year ago
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    What will be the perimeter and the area of the rectangle below if it is enlarged using a scale factor of 4.5? A rectangle is shown. The length of the rectangle is labeled as 8 cm, and the width is labeled as 6 cm. Perimeter = 46 cm, area = 131.25 cm2 Perimeter = 126 cm, area = 972 cm2 Perimeter = 46 cm, area = 972 cm2 Perimeter = 126 cm, area = 131.25 cm2 got anything?

  2. welshfella
    • one year ago
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    use implicit differentiation

  3. anonymous
    • one year ago
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    Is that when you set it equal to y and then derive it?

  4. welshfella
    • one year ago
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    find the derivative with respect to x term by term

  5. anonymous
    • one year ago
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    So I would get 2x=lnxy first correct?

  6. welshfella
    • one year ago
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    you treat y as a function of x

  7. anonymous
    • one year ago
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    Im confused.

  8. welshfella
    • one year ago
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    the 2x is correct but you use the Chain and product Rules to differentiate the right side

  9. welshfella
    • one year ago
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    2x = (1/ (xy) * (x dy/dx + y) now you make dy/dx the subject

  10. anonymous
    • one year ago
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    What do you mean by make it the subject? Like solve for that?

  11. welshfella
    • one year ago
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    |dw:1435856245509:dw|

  12. welshfella
    • one year ago
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    yes solve for dy/dx

  13. anonymous
    • one year ago
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    Would it be 2x^2y=dy/dx?

  14. welshfella
    • one year ago
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    dy/dx = y( 2x + 1/x)

  15. welshfella
    • one year ago
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    sorry that's dy/dx = y (2x - 1/x)

  16. anonymous
    • one year ago
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    Okay and then with that would I plug in the given values?

  17. welshfella
    • one year ago
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    ckeck my algebra

  18. welshfella
    • one year ago
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    yes plug in x = 1 and y = e

  19. anonymous
    • one year ago
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    So it would just equal e correct?

  20. welshfella
    • one year ago
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    dy/dx = e(2 - 1/e) = 2e - 1

  21. anonymous
    • one year ago
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    You divided by e when you should divide by x, which is 1.

  22. welshfella
    • one year ago
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    oh so I did!! your are correct its e

  23. anonymous
    • one year ago
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    Okay thank you so much for you help!!!

  24. welshfella
    • one year ago
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    yw

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