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krypton

  • 2 years ago

i need help with number 3 a and b

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  1. krypton
    • 2 years ago
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  2. krypton
    • 2 years ago
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    pls help

  3. ivanmlerner
    • 2 years ago
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    The opposite of derivative is integration, so in a you need to integrate once and on b, twice. Since the indefinite integral (with no limits of integration) gives you an arbitrary constant that disapears when you derivate, you need a way to find that constant because any number would satisfy the derivative formula since it would disapear when you derivated, thats why they give you one value of the function you want to find. Is it too confusing the way I explained or you got it?

  4. krypton
    • 2 years ago
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    b was the confusing one,so am to integrate t-cosx 2twice?

  5. ivanmlerner
    • 2 years ago
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    Yes, because you are derivating twice, but then you get 2 arbitrary constants.

  6. krypton
    • 2 years ago
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    whats this for dy(0)/dx=2 what do i need it for?

  7. krypton
    • 2 years ago
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    my first integration i got tx-sin(x)+c

  8. ivanmlerner
    • 2 years ago
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    Your integration is fine and now you need to determine c, thats when you use dy(0)/dx=2, because by integrating once, you got dy/dx

  9. krypton
    • 2 years ago
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    so how do i use this dy(0)/dx=2?

  10. ivanmlerner
    • 2 years ago
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    tx-sin(x)+c=dy/dx so t*0-sin(0)+c=2 Do you understand that?

  11. krypton
    • 2 years ago
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    yeah

  12. krypton
    • 2 years ago
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    so what about the y(0)=-2?

  13. ivanmlerner
    • 2 years ago
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    you have dy/dx, but you want y, so you integrate again, and youll need this to find the other constant.

  14. ivanmlerner
    • 2 years ago
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    So, did you got the answer?

  15. krypton
    • 2 years ago
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    i will integrate this tx-sin(x)+c again?

  16. ivanmlerner
    • 2 years ago
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    yes

  17. ivanmlerner
    • 2 years ago
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    because it is equal to dy/dx, and you want y

  18. krypton
    • 2 years ago
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    i got (tx^2/2)+cos(x)+c

  19. ivanmlerner
    • 2 years ago
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    you forgot to sonsider the constant of the previous integration

  20. ivanmlerner
    • 2 years ago
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    There will be two constants in this case, because its the second derivative.

  21. krypton
    • 2 years ago
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    cx+tx^2/2+cos(x)+c?

  22. ivanmlerner
    • 2 years ago
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    Yep thats it, but keep in mind that the c's are different, and the first one you should already have it as a number

  23. krypton
    • 2 years ago
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    the 1st one is 2 right?

  24. ivanmlerner
    • 2 years ago
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    yes

  25. krypton
    • 2 years ago
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    ok thanks alot for your help :)

  26. ivanmlerner
    • 2 years ago
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    You are welcome

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