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anonymous

  • 4 years ago

I need someone to walk me through a couple of problems. The first is f(x)= lxl+1find the domain algebraically.

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  1. anonymous
    • 4 years ago
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    unless otherwise specified the domain will be all real numbers, since you can take the absolute value of anything

  2. myininaya
    • 4 years ago
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    I agree with satellite's diagnosis.

  3. anonymous
    • 4 years ago
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    the real truth is that you should specify the domain of the function when you define it, but if you don't it is assumed to be the largest set of numbers on which the function can act, so in this case anything

  4. anonymous
    • 4 years ago
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    I need to show algebra for credit

  5. anonymous
    • 4 years ago
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    sorry but there is no algebra to do here

  6. myininaya
    • 4 years ago
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    There is no algebra to show.

  7. anonymous
    • 4 years ago
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    math is not about algebra, math is about reasoning

  8. anonymous
    • 4 years ago
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    ok how about 2x^3-5x+6

  9. myininaya
    • 4 years ago
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    It is a polynomial. Those things exist for any input x which means its domain is all read numbers

  10. anonymous
    • 4 years ago
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    polynomial domain is still all real numbers. you only have to worry about division by zero, or taking a even root of a negative number. both of those are not allowed, but most things are permitted

  11. anonymous
    • 4 years ago
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    The instructions are to find the domain algebraically. You set the function =0 and solve. I am not sure how to do this on these problems.

  12. anonymous
    • 4 years ago
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    again, no algebra to show

  13. myininaya
    • 4 years ago
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    Are you sure it says find domain and not x-intercepts?

  14. anonymous
    • 4 years ago
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    setting the function = 0 tells you where it is zero, not what the domain is

  15. anonymous
    • 4 years ago
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    yes I am sure and I realize that this tells me the zero but it is what I have to do in order to get credit. Going through and stating only domain with no work gets me nothing. I have to find the zero.

  16. anonymous
    • 4 years ago
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    Finding the zero is not equivalent to finding the domain

  17. anonymous
    • 4 years ago
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    those are separate problems and are unrelated

  18. anonymous
    • 4 years ago
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    I understand what you all are saying. I am saying I have to find the zero to get credit for work. Would it help if I asked you to show me how to find the zero for these?

  19. Mertsj
    • 4 years ago
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    You could say that |x| >=0 for all real numbers so the domain is all real numbers.

  20. anonymous
    • 4 years ago
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    There is no zero for f(x)=|x|+1

  21. anonymous
    • 4 years ago
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    because |x| can never = -1

  22. anonymous
    • 4 years ago
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    \[|x|+1\geq 1\] so it is never zero

  23. anonymous
    • 4 years ago
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    what about 2x^3-5x+6?

  24. myininaya
    • 4 years ago
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    So we can try syntehtic division to find rational solutions but this does not guarantee there are rational solutions

  25. Mertsj
    • 4 years ago
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    Did you perhaps say domain when you meant range?

  26. anonymous
    • 4 years ago
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    No, I need to find the zero

  27. myininaya
    • 4 years ago
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    i be right back using synthetic division and trail and error and finding zeros I found one zero to be x=-2

  28. myininaya
    • 4 years ago
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    |dw:1327795208134:dw|

  29. myininaya
    • 4 years ago
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    \[2x^2-4x+3=0\] solving this equation will give you the other two zeros

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