Math Problem Statement

Evaluate the integrals provided in the image.

Solution

It looks like you uploaded an image containing several math problems related to integration. Let's break them down one by one.

I’ll walk through each of the problems, so you can better understand how to approach solving them.


Problem 1:
(2x+3)dx\int \left( 2 \sqrt{x} + 3 \right) \, dx

This is an indefinite integral. To solve it, we can apply basic integration rules:

  • For 2x2 \sqrt{x}, rewrite as 2x1/22x^{1/2}. The integral of xnx^n is xn+1n+1\frac{x^{n+1}}{n+1}, so you’ll add 1 to the exponent and divide by the new exponent.
  • For 3, the integral is simply 3x3x.

Solution: (2x1/2+3)dx=43x3/2+3x+C\int \left( 2x^{1/2} + 3 \right) \, dx = \frac{4}{3} x^{3/2} + 3x + C


Problem 2:
Evaluate the definite integral: 02dxx2+3\int_0^2 \frac{dx}{x^2 + 3}

This is a rational function, and we can use a standard formula for the integral of 1x2+a2\frac{1}{x^2 + a^2}, which is 1aarctan(xa)\frac{1}{a} \arctan\left(\frac{x}{a}\right). For this problem, a2=3a^2 = 3, so a=3a = \sqrt{3}.

Solution: dxx2+3=13arctan(x3)\int \frac{dx}{x^2 + 3} = \frac{1}{\sqrt{3}} \arctan\left(\frac{x}{\sqrt{3}}\right)

Evaluating from 0 to 2: 13[arctan(23)arctan(0)]\frac{1}{\sqrt{3}} \left[\arctan\left(\frac{2}{\sqrt{3}}\right) - \arctan(0)\right]

This requires finding the arctangent of 2/32/\sqrt{3}.


Problem 3:
Evaluate the definite integral: 03sin(2t)dt\int_0^3 \sin(2t) \, dt

The integral of sin(2t)\sin(2t) is straightforward. Use the antiderivative of sin(kx)\sin(kx), which is 1kcos(kx)-\frac{1}{k} \cos(kx).

Solution: sin(2t)dt=12cos(2t)\int \sin(2t) \, dt = -\frac{1}{2} \cos(2t)

Evaluating from 0 to 3: 12[cos(6)cos(0)]-\frac{1}{2} \left[\cos(6) - \cos(0)\right]


Problem 4:
Evaluate the definite integral: 055sin(x)cos(x)dx\int_0^5 5 \sin(x) \cos(x) \, dx

Use the identity 2sin(x)cos(x)=sin(2x)2 \sin(x) \cos(x) = \sin(2x) to simplify this. After applying that identity:

Solution: 055sin(x)cos(x)dx=5205sin(2x)dx\int_0^5 5 \sin(x) \cos(x) \, dx = \frac{5}{2} \int_0^5 \sin(2x) \, dx

The integral of sin(2x)\sin(2x) is 12cos(2x)-\frac{1}{2} \cos(2x), so we evaluate this from 0 to 5.


Problem 5:
Evaluate the indefinite integral: 7x+7x2+1dx\int \frac{7x + 7}{x^2 + 1} \, dx

This integral involves a rational function, and we can split the numerator: 7xx2+1dx+7x2+1dx\int \frac{7x}{x^2 + 1} \, dx + \int \frac{7}{x^2 + 1} \, dx

For the first term, use the substitution u=x2+1u = x^2 + 1, and the second term is a standard arctangent integral.


Problem 6:
Evaluate the indefinite integral: (arcsin(x))91x2dx\int \frac{(\arcsin(x))^9}{\sqrt{1 - x^2}} \, dx

This is a complicated integral, but recognizing that the term 11x2\frac{1}{\sqrt{1 - x^2}} is the derivative of arcsin(x)\arcsin(x), this suggests a substitution approach.


Would you like to go through any of these problems in more detail, or do you need further clarification on any steps? Let me know!

Here are a few questions to dive deeper:

  1. How does substitution work in solving integrals like 7xx2+1dx\int \frac{7x}{x^2 + 1} \, dx?
  2. Why do we use the identity 2sin(x)cos(x)=sin(2x)2 \sin(x) \cos(x) = \sin(2x) in integrals?
  3. What are some common techniques for solving trigonometric integrals?
  4. How does the constant of integration, +C+ C, appear in indefinite integrals?
  5. What are the key differences between definite and indefinite integrals in terms of evaluation?

Tip: For definite integrals, always remember to substitute the limits after finding the antiderivative, not before!

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Math Problem Analysis

Mathematical Concepts

Indefinite Integrals
Definite Integrals
Trigonometric Integrals
Rational Functions
Substitution in Integration

Formulas

Integral of x^n: (x^(n+1)) / (n+1)
Integral of 1 / (x^2 + a^2): 1/a * arctan(x/a)
Integral of sin(kx): -1/k * cos(kx)
Integral of arcsin(x): (arcsin(x))^9 / sqrt(1 - x^2)

Theorems

Fundamental Theorem of Calculus
Trigonometric Identities for Simplification

Suitable Grade Level

Grades 11-12