Math Problem Statement

find the integral of (3^(3sqrtx-2))/2sqrtx dx

Solution

We are tasked with finding the integral of the function:

33x22xdx\int \frac{3^{3\sqrt{x} - 2}}{2\sqrt{x}} \, dx

Step-by-Step Solution:

Step 1: Substitution

Let’s first set a substitution to simplify the expression:

Let u=x=x1/2u = \sqrt{x} = x^{1/2}, so that: dudx=12x    dx=2udu\frac{du}{dx} = \frac{1}{2\sqrt{x}} \implies dx = 2u \, du

This transforms x\sqrt{x} to uu, and the integral becomes: 33u22u2udu\int \frac{3^{3u - 2}}{2u} \cdot 2u \, du

The 2u2u terms cancel out, and we are left with: 33u2du\int 3^{3u - 2} \, du

Step 2: Break the exponent

We can express the exponent 3u23u - 2 as: 33u2=33u32=33u93^{3u - 2} = \frac{3^{3u}}{3^2} = \frac{3^{3u}}{9}

Thus, the integral becomes: 1933udu\frac{1}{9} \int 3^{3u} \, du

Step 3: Another substitution

Now, let’s perform another substitution. Let v=3uv = 3u, so that: dv=3du    du=dv3dv = 3 \, du \implies du = \frac{dv}{3}

Thus, the integral becomes: 193vdv3=1273vdv\frac{1}{9} \int 3^v \cdot \frac{dv}{3} = \frac{1}{27} \int 3^v \, dv

Step 4: Integrate

The integral of 3v3^v with respect to vv is: 3vdv=3vln(3)\int 3^v \, dv = \frac{3^v}{\ln(3)}

Thus, the result of the integral is: 1273vln(3)=3v27ln(3)\frac{1}{27} \cdot \frac{3^v}{\ln(3)} = \frac{3^v}{27\ln(3)}

Step 5: Back-substitute vv and uu

Now, substitute back v=3uv = 3u and u=xu = \sqrt{x}: 33u27ln(3)=33x27ln(3)\frac{3^{3u}}{27\ln(3)} = \frac{3^{3\sqrt{x}}}{27\ln(3)}

Thus, the final answer is: 33x22xdx=33x27ln(3)+C\int \frac{3^{3\sqrt{x} - 2}}{2\sqrt{x}} \, dx = \frac{3^{3\sqrt{x}}}{27\ln(3)} + C

where CC is the constant of integration.


Would you like more details or have any questions?

Here are 5 related questions for further practice:

  1. What is the integral of exxdx\frac{e^{\sqrt{x}}}{\sqrt{x}} \, dx?
  2. Find the derivative of 33x3^{3\sqrt{x}}.
  3. How do you perform substitution for integrals involving square roots?
  4. Solve axxdx\int \frac{a^{\sqrt{x}}}{\sqrt{x}} \, dx, where aa is a constant.
  5. Evaluate 32xdx\int 3^{2x} \, dx.

Tip: For integrals involving exponential functions, consider substitutions that simplify the exponent before integrating.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Integral Calculus
Substitution Method
Exponential Functions

Formulas

u = sqrt(x) => du/dx = 1/(2sqrt(x))
∫ a^x dx = a^x / ln(a) + C

Theorems

Power Rule for Integration
Exponential Integration Rule

Suitable Grade Level

Undergraduate - Calculus I/II