Math Problem Statement

integrate sqrt(5-2x) from -2 to 0

Solution

To integrate the function 52x\sqrt{5 - 2x} from 2-2 to 00, we can use the method of substitution.

Step-by-Step Solution:

  1. Substitution: Let u=52xu = 5 - 2x. Then, differentiate uu with respect to xx:

    dudx=2    dx=12du\frac{du}{dx} = -2 \implies dx = -\frac{1}{2} du

  2. Change of limits: When x=2x = -2, u=52(2)=9u = 5 - 2(-2) = 9.

    When x=0x = 0, u=52(0)=5u = 5 - 2(0) = 5.

    So the integral in terms of uu is now from u=9u = 9 to u=5u = 5.

  3. Rewrite the integral: Substitute uu and dxdx into the integral:

    2052xdx=95u(12du)\int_{-2}^{0} \sqrt{5 - 2x} \, dx = \int_{9}^{5} \sqrt{u} \left(-\frac{1}{2} du\right)

    =1295u1/2du= -\frac{1}{2} \int_{9}^{5} u^{1/2} \, du

  4. Integrate: Now we integrate u1/2u^{1/2}:

    =12[23u3/2]95= -\frac{1}{2} \left[ \frac{2}{3} u^{3/2} \right]_{9}^{5}

    =13[u3/2]95= -\frac{1}{3} \left[ u^{3/2} \right]_{9}^{5}

  5. Evaluate at the limits:

    =13(53/293/2)= -\frac{1}{3} \left( 5^{3/2} - 9^{3/2} \right)

    Calculate the values:

    • 53/2=555^{3/2} = 5 \cdot \sqrt{5}
    • 93/2=99=279^{3/2} = 9 \cdot \sqrt{9} = 27

    =13(5527)= -\frac{1}{3} \left( 5\sqrt{5} - 27 \right)

  6. Final answer:

    =27553= \frac{27 - 5\sqrt{5}}{3}

This is the evaluated result of the integral 2052xdx\int_{-2}^{0} \sqrt{5 - 2x} \, dx.

Do you want further details or have any questions?

Here are some related questions you might find interesting:

  1. How do you use substitution for more complex integrals?
  2. What are the different methods for solving definite integrals?
  3. How do you handle improper integrals with square root functions?
  4. How can you confirm the result of an integral using numerical methods?
  5. What are the applications of definite integrals in real-world problems?

Tip: When substituting variables, always remember to change the limits of integration accordingly.

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Math Problem Analysis

Mathematical Concepts

Integral calculus
Substitution method
Definite integrals

Formulas

Substitution rule for integrals

Theorems

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Suitable Grade Level

Grades 11-12