Discover new information and insights with the help of IDNLearn.com. Our community provides timely and precise responses to help you understand and solve any issue you face.

Evaluate the integral using integration by parts with the indicated choices of u and dv. (Use C for the constant of integration.) xe7x dx; u

Sagot :

Answer:

[tex]\displaystyle \int {xe^{7x}} \, dx = \frac{e^{7x}}{7} \bigg( x - \frac{1}{7} \bigg) + C[/tex]

General Formulas and Concepts:

Calculus

Differentiation

  • Derivatives
  • Derivative Notation

Derivative Property [Multiplied Constant]:                                                           [tex]\displaystyle \frac{d}{dx} [cf(x)] = c \cdot f'(x)[/tex]

Basic Power Rule:

  1. f(x) = cxⁿ
  2. f’(x) = c·nxⁿ⁻¹

Integration

  • Integrals

Integration Property [Multiplied Constant]:                                                         [tex]\displaystyle \int {cf(x)} \, dx = c \int {f(x)} \, dx[/tex]

U-Substitution

Integration by Parts:                                                                                               [tex]\displaystyle \int {u} \, dv = uv - \int {v} \, du[/tex]

  • [IBP] LIPET: Logs, inverses, Polynomials, Exponentials, Trig

Step-by-step explanation:

Step 1: Define

Identify

[tex]\displaystyle \int {xe^{7x}} \, dx[/tex]

Step 2: Integrate Pt. 1

Identify variables for integration by parts using LIPET.

  1. Set u:                                                                                                             [tex]\displaystyle u = x[/tex]
  2. [u] Basic Power Rule:                                                                                     [tex]\displaystyle du = dx[/tex]
  3. Set dv:                                                                                                           [tex]\displaystyle dv = e^{7x} \ dx[/tex]
  4. [dv] Exponential Integration [U-Substitution]:                                             [tex]\displaystyle v = \frac{e^{7x}}{7}[/tex]

Step 3: integrate Pt. 2

  1. [Integral] Integration by Parts:                                                                      [tex]\displaystyle \int {xe^{7x}} \, dx = \frac{xe^{7x}}{7} - \int {\frac{e^{7x}}{7}} \, dx[/tex]
  2. [Integral] Rewrite [Integration Property - Multiplied Constant]:                 [tex]\displaystyle \int {xe^{7x}} \, dx = \frac{xe^{7x}}{7} - \frac{1}{7} \int {e^{7x}} \, dx[/tex]

Step 4: Integrate Pt. 3

Identify variables for u-substitution.

  1. Set u:                                                                                                             [tex]\displaystyle u = 7x[/tex]
  2. [u] Basic Power Rule [Derivative Property - Multiplied Constant]:             [tex]\displaystyle du = 7 \ dx[/tex]

Step 5: Integrate Pt. 4

  1. [Integral] Rewrite [Integration Property - Multiplied Constant]:                 [tex]\displaystyle \int {xe^{7x}} \, dx = \frac{xe^{7x}}{7} - \frac{1}{49} \int {7e^{7x}} \, dx[/tex]
  2. [Integral] U-Substitution:                                                                               [tex]\displaystyle \int {xe^{7x}} \, dx = \frac{xe^{7x}}{7} - \frac{1}{49} \int {e^u} \, dx[/tex]
  3. [Integral] Exponential Integration:                                                               [tex]\displaystyle \int {xe^{7x}} \, dx = \frac{xe^{7x}}{7} - \frac{e^u}{49} + C[/tex]
  4. [u] Back-Substitute:                                                                                       [tex]\displaystyle \int {xe^{7x}} \, dx = \frac{xe^{7x}}{7} - \frac{e^{7x}}{49} + C[/tex]
  5. Factor:                                                                                                           [tex]\displaystyle \int {xe^{7x}} \, dx = \frac{e^{7x}}{7} \bigg( x - \frac{1}{7} \bigg) + C[/tex]

Topic: AP Calculus AB/BC (Calculus I/I + II)

Unit: Integration