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angelwings996

  • one year ago

What is the solution of the equation? (x - 2)^3/4 = 8

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  1. abb0t
    • one year ago
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    multiply by 4 and cube everything. then add 2 to solve for x.

  2. angelwings996
    • one year ago
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    \[(x - 2)^{3/4} = 8 \] is the equation

  3. abb0t
    • one year ago
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    That's the same thing as: \[\sqrt[4]{a^3}\]

  4. angelwings996
    • one year ago
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    @abb0t will there only be one solution?

  5. mominanisar
    • one year ago
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    ((x - 2)^1/4)^3 = 8 =2^3 it powers are same then you can compare the bases i.e (x - 2)^1/4 = 2 then multiply the both sides with ^4 then you will get x-2=16 x=18

  6. wio
    • one year ago
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    This one won't have multiple solutions.

  7. Saikam
    • one year ago
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    its like (x-2)^3 = 8^4 giving you x = 18. And only 1 root

  8. angelwings996
    • one year ago
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    @mominanisar Thanks!

  9. angelwings996
    • one year ago
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    Could any of you help me with one more please?

  10. mominanisar
    • one year ago
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    no problem

  11. angelwings996
    • one year ago
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    You live near a bridge that goes over a river. The underside of the bridge is an arch that can be modeled with the function y = -0.000471x^2 + .837x where x and y are measured in feet. How high above the river is the bridge (the top of the arch)? Hw long is the section of bridge above the arch?

  12. angelwings996
    • one year ago
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    @mominanisar @Saikam could either of you help me please?

  13. angelwings996
    • one year ago
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    It is multiple choice so I can list them

  14. mominanisar
    • one year ago
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    yes i will if i am able to

  15. angelwings996
    • one year ago
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    Okay, ill give you the choices

  16. Saikam
    • one year ago
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    actaully, the length of the section of bridge and its height above the river are dependant on each other. one cannot be determined without the other

  17. angelwings996
    • one year ago
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    a. The bridge is about 1,777.07 ft. above the river, and the length of the bridge above the arch is about 888.54 ft. b. The bridge is about 371.85 ft. above the river, and the length of the bridge above the arch is about 1,777.07 ft. c. The bridge is about 371.85 ft. above the river, and the length of the bridge above the arch is about 888.54 ft. d. The bridge is about 1,777.07 ft. above the river, and the length of the bridge above the arch is about 371.85 ft.

  18. angelwings996
    • one year ago
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    @Saikam That's what everyone is saying, so Im not able to find the answer anywhere. Im not even sure how you would figure this out

  19. mominanisar
    • one year ago
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    i agree with @Saikam

  20. angelwings996
    • one year ago
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    Then would I have to take an educated guess on this?

  21. Saikam
    • one year ago
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    no. we must consider each option and verify. take the length of bridge given in the first option, then check if it satisfies the given height. Then take the values from second option, and so on... one (or more) of them might satisfy. can u try? or u want me to help?

  22. angelwings996
    • one year ago
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    Could you help me please?

  23. jim_thompson5910
    • one year ago
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    |dw:1358145028404:dw|

  24. jim_thompson5910
    • one year ago
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    |dw:1358145052483:dw|

  25. jim_thompson5910
    • one year ago
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    height of bridge above water = y coordinate of vertex length of the bridge above the arch = distance between the two roots

  26. Saikam
    • one year ago
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    No @jim_thompson5910 because the question doesnt say that the x-axis is the level of the river. it could be anything. like y=1, y=-1 , etc.that is why the verification needed

  27. angelwings996
    • one year ago
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    If you guys can't figure it out its okay(:

  28. jim_thompson5910
    • one year ago
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    well it's implicit, they should state it more clearly though

  29. jim_thompson5910
    • one year ago
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    y = height above the ground

  30. jim_thompson5910
    • one year ago
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    or river, i meant

  31. angelwings996
    • one year ago
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    I agree...Ít's hard to do the math to something when you don't quite understand the question

  32. Saikam
    • one year ago
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    dy/dx = 0 gives you the x-xoordinate, where the arch has its vertex 0 = -0.000942 x + 0.837 2x = 0.837/0.000471 This could be equated to length of the river 2x = 1000*(837/471) = 1777.07 ft for which the only option matching is b :P

  33. angelwings996
    • one year ago
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    So b?

  34. Saikam
    • one year ago
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    you should substitute this value of x (x, and not 2x )in the equation and check for y . If its equal to 371.85, then yea, B. I just woke up. feeling lazy to do the calculations.

  35. angelwings996
    • one year ago
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    Lol its fine. I appreciate both of your helps! Thank you (:

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