IntegralsEasy

Indefinite integral — power and logarithm

Calculate the indefinite integral ∫ (3x² + 2/x) dx.
Given data
∫ (3x² + 2/x) dx
Review the theory: Integrali
Steps
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  1. Integrate term by term: ∫ 3x² dx = ?
  2. Integrate ∫ (2/x) dx = ?
  3. Combine the results. What is the total integral?
Full worked solution
  1. Integrate term by term: ∫ 3x² dx = ?
    ∫3x2 dx=3⋅x33=x3\int 3x^2\,dx = 3 \cdot \dfrac{x^3}{3} = x^3
    ∫3x2 dx=3⋅x33+C1=x3+C1\int 3x^2\,dx = 3 \cdot \frac{x^{3}}{3} + C_1 = \mathbf{x^3} + C_1. Applying the power rule ∫xndx=xn+1/(n+1)\int x^n dx = x^{n+1}/(n+1) with n=2n = 2.
  2. Integrate ∫ (2/x) dx = ?
    ∫2x dx=2ln⁡∣x∣\int \dfrac{2}{x}\,dx = 2\ln|x|
    ∫2x dx=2ln⁡∣x∣+C2\int \frac{2}{x}\,dx = 2\ln|x| + C_2. The integral of 1/x1/x is ln⁡∣x∣\ln|x|, a standard result.
  3. Combine the results. What is the total integral?
    ∫(3x2+2/x) dx=x3+2ln⁡∣x∣+C\int (3x^2 + 2/x)\,dx = x^3 + 2\ln|x| + C
    ∫(3x2+2/x) dx=x3+2ln⁡∣x∣+C\int (3x^2 + 2/x)\,dx = x^3 + 2\ln|x| + \mathbf{C}. Combining the two terms and adding a single arbitrary constant C=C1+C2C = C_1 + C_2.
Result:x³ + 2 ln|x| + C.