Math Problem Statement

Multiple-choice Laplace transform questions including problems like L(2 + e^(-3t) + sin(4t)), L(sin(3t - 2)), and other related transforms.

Solution

The image contains a set of Laplace transform-related multiple-choice problems. Let's go through the questions step by step, starting with the first one:

1. L{2+e3t+sin4t}\mathcal{L}\{2 + e^{-3t} + \sin 4t\}

The Laplace transform of:

  • 22 is 2s\frac{2}{s},
  • e3te^{-3t} is 1s+3\frac{1}{s + 3},
  • sin(4t)\sin(4t) is 4s2+16\frac{4}{s^2 + 16}.

Summing them up, we get: 2s+1s+3+4s2+16\frac{2}{s} + \frac{1}{s + 3} + \frac{4}{s^2 + 16} The correct answer is (d).

2. L{sin(3t2)}\mathcal{L}\{\sin(3t - 2)\}

Using the phase shift property of the Laplace transform: L{sin(3t)}=3s2+9\mathcal{L}\{\sin(3t)\} = \frac{3}{s^2 + 9} But due to the time-shift, we apply Euler's identity, which leads to additional terms. The correct answer appears to be (d).

3. L{tsin(2t)}\mathcal{L}\{t \sin(2t)\}

Using the formula L{tsin(at)}=2s(s2+a2)2\mathcal{L}\{t \sin(at)\} = \frac{2s}{(s^2 + a^2)^2} for a=2a = 2: The correct answer is (b).

4. L{e3tcosh(2t)}\mathcal{L}\{e^{3t} \cosh(2t)\}

We use the Laplace transform of cosh(at)\cosh(at), adjusted by the exponential term: The correct answer is (b).

5. L{tsin(4t)}\mathcal{L}\{t \sin(4t)\}

From the known formula for tsin(at)t \sin(at), the Laplace transform is: L{tsin(at)}=2s(s2+a2)2\mathcal{L}\{t \sin(at)\} = \frac{2s}{(s^2 + a^2)^2} For a=4a = 4, the correct answer is (a).

Do you want me to continue with more detailed steps, or do you have any questions about the explanation so far?

Here are 5 related questions:

  1. What is the Laplace transform of cos(at)\cos(at)?
  2. How do phase shifts affect the Laplace transform?
  3. What is the inverse Laplace transform of 1s2+a2\frac{1}{s^2 + a^2}?
  4. How does the time-shift theorem modify the Laplace transform?
  5. What is the Laplace transform of tneatt^n e^{at}?

Tip: Use known Laplace transform tables for common functions to speed up solving problems!

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Math Problem Analysis

Mathematical Concepts

Laplace Transforms
Inverse Laplace Transforms
Complex Numbers
Differential Equations

Formulas

L{e^(-at)} = 1/(s + a)
L{sin(at)} = a / (s^2 + a^2)
L{cos(at)} = s / (s^2 + a^2)
L{t*sin(at)} = 2s / (s^2 + a^2)^2

Theorems

Laplace Transform Theorem
Shifting Theorem
Inverse Laplace Theorem
Convolution Theorem

Suitable Grade Level

University Level (Undergraduate)