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anonymous

  • one year ago

Let f(x) = x2 + x + 2 and g(x) = 2x2 + 5. Find f(g(x)). Show each step of your work

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  1. anonymous
    • one year ago
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    Substitute all x of f(x) to 2x^2+5.

  2. anonymous
    • one year ago
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    |dw:1438121254032:dw|

  3. anonymous
    • one year ago
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    You there?

  4. anonymous
    • one year ago
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    Did you understand it or do you need more help?

  5. anonymous
    • one year ago
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    yea im here

  6. anonymous
    • one year ago
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    i probably need more help. im having a lot of trouble with this stuff

  7. anonymous
    • one year ago
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    Okay so can you tell me the function now after you substitute x as g(x)?

  8. anonymous
    • one year ago
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    Just make all x as 2x^2+5, then combine like terms.

  9. anonymous
    • one year ago
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    oh okay, is that all?

  10. anonymous
    • one year ago
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    Yes. Could you press the "draw" button and try to show me the function?

  11. anonymous
    • one year ago
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    f(x)= (2x^2)^2 + 2x^2 +5 +2

  12. anonymous
    • one year ago
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    like so?

  13. anonymous
    • one year ago
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    Is this your function? |dw:1438121804638:dw|

  14. anonymous
    • one year ago
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    yup

  15. anonymous
    • one year ago
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    I think you forget something. :) What is g(x) again?

  16. anonymous
    • one year ago
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    forgot*

  17. anonymous
    • one year ago
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    oh i see my error. let me try again

  18. anonymous
    • one year ago
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    Go ahead.

  19. anonymous
    • one year ago
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    |dw:1438122029529:dw|

  20. anonymous
    • one year ago
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    i forgot the +5

  21. anonymous
    • one year ago
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    Yes. :) Now solve it.

  22. anonymous
    • one year ago
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    Start with this. |dw:1438122119288:dw|

  23. anonymous
    • one year ago
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    Are you having any difficulty so far?

  24. anonymous
    • one year ago
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    |dw:1438122304749:dw|

  25. anonymous
    • one year ago
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    There's something missing. Try the FOIL method.|dw:1438122345260:dw|

  26. anonymous
    • one year ago
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    is it 4x^4 + 20x^2+25

  27. anonymous
    • one year ago
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    Great! So the function is now |dw:1438122528248:dw|

  28. anonymous
    • one year ago
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    Combine like terms.

  29. anonymous
    • one year ago
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    4x^4 + 14x^2 + 32

  30. anonymous
    • one year ago
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    There's no subtraction in the function.

  31. anonymous
    • one year ago
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    |dw:1438122865261:dw|