Bory asked in Science & MathematicsMathematics · 11 months ago

U substitution?

integral (x^2+2) sin(2x^3 + 6x)dx

i set u as 2x^3 + 6x.

du is 6x^2 + 6.

Do i factor it more or dx=du/ 6x^2 + 6

Update:

its (x^2 +1) not (x^2+2)

1 Answer

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  • Pope
    Lv 7
    11 months ago
    Favorite Answer

    You were doing fine. I would not try to factor anything. Just proceed with the substitutions.

    u = 2x³ + 6x

    du/dx = 6x² + 6

    du = (6x² + 6) dx

    ∫ (6x² + 6)sin(2x³ + 6x) dx = ∫ sin(u) du

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    • Bory11 months agoReport

      oops sorry, i was being a dummy again. (x^2 + 1)/6x^2 + 6 = 1/6 you are absolutely correct sorry

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