Chapter 30

Technical Mathematics with Calculus · 101 exercises

Problem 10

Solve each differential equation. $$3 D y=5 x+2$$

5 step solution

Problem 11

Find the general solution of each differential equation. Try some by calculator. $$(2 x-y) y^{\prime}=x-2 y$$

7 step solution

Problem 11

Find the general solution to each differential equation. $$y^{\prime}=\frac{2-4 x^{2} y}{x+x^{3}}$$

7 step solution

Problem 11

An instrument package is dropped from an airplane. It falls from rest through air whose resisting force is proportional to the speed of the package. The terminal speed is \(155 \mathrm{ft} / \mathrm{s}\). Show that the acceleration is given by the differential equation \(a=d v / d t=g-g v / 155\)

5 step solution

Problem 11

Solve each differential equation. $$d y=x^{2} d x$$

3 step solution

Problem 12

Find the general solution to each differential equation. $$(x+1) y^{\prime}=2(x+y+1)$$

6 step solution

Problem 12

Solve each differential equation. $$d y-4 x d x=0$$

4 step solution

Problem 13

Find the general solution to each differential equation. $$x y^{\prime}+x^{2} y+y=0$$

6 step solution

Problem 13

Show that each function is a solution to the given differential equation. $$y^{\prime}=\frac{2 y}{x}, y=C x^{2}$$

4 step solution

Problem 14

Find the general solution of each differential equation. Try some by calculator. $$\left(x-2 x^{2} y\right) d y=y d x$$

7 step solution

Problem 14

Find the general solution to each differential equation. $$\left(1+x^{3}\right) d y=\left(1-3 x^{2} y\right) d x$$

5 step solution

Problem 14

Show that each function is a solution to the given differential equation. $$\frac{d y}{d x}=\frac{x^{2}}{y^{3}}, 4 x^{3}-3 y^{4}=C$$

3 step solution

Problem 15

For the circuit of Fig. \(30-13, R=233 \Omega, L=5.82 \mathrm{H},\) and \(E=58.0 \mathrm{sin} 377 t \mathrm{V}\). If the switch is closed when \(E\) is zero and increasing, show that the current is given by \(i=26.3 \sin \left(377 t-83.9^{\circ}\right)+26.1 e^{-40 t} \mathrm{mA}.\)

7 step solution

Problem 15

Find the general solution to each differential equation. $$y^{\prime}+y=e^{x}$$

6 step solution

Problem 15

Show that each function is a solution to the given differential equation. $$D y=\frac{2 y}{x}, y=C x^{2}$$

4 step solution

Problem 16

Find the general solution of each differential equation. Try some by calculator. $$(y-x) y^{\prime}+2 x y^{2}+y=0$$

5 step solution

Problem 16

Find the general solution to each differential equation. Try some by calculator. $$y^{\prime}=\frac{e^{x-y}}{e^{x}+1}$$

6 step solution

Problem 16

Show that each function is a solution to the given differential equation. $$y^{\prime} \cot x+3+y=0, y=C \cos x-3$$

5 step solution

Problem 17

Find the general solution of each differential equation. Try some by calculator. $$3 x-2 y^{2}-4 x y y^{\prime}=0$$

8 step solution

Problem 17

Find the general solution to each differential equation. $$y^{\prime}=2 y+4 e^{2 x}$$

5 step solution

Problem 18

Find the general solution to each differential equation. $$x y^{\prime}-e^{x}+y+x y=0$$

6 step solution

Problem 18

A box falls from rest and encounters air resistance proportional to the cube of the speed. The limiting speed is \(12.5 \mathrm{ft} / \mathrm{s}\). Show that the acceleration is given by the differential equation \(60.7 d v / d t=1953-v^{3}\)

6 step solution

Problem 18

With Exponential Functions $$d y=e^{-x} d x$$

6 step solution

Problem 19

Using the given boundary condition, find the particular solution to each differential equation. $$4 x=y+x y^{\prime}, x=3 \text { when } y=1$$

8 step solution

Problem 19

Find the general solution to each differential equation. $$y^{\prime}=\frac{4 \ln x-2 x^{2} y}{x^{3}}$$

3 step solution

Problem 19

With Exponential Functions $$y e^{2 x}=\left(1+e^{2 x}\right) y^{\prime}$$

6 step solution

Problem 20

Using the given boundary condition, find the particular solution to each differential equation. $$y d x=\left(x-2 x^{2} y\right) d y, x=1 \text { when } y=2$$

6 step solution

Problem 20

$$y^{\prime}+y \sin x=3 \sin x$$

6 step solution

Problem 20

With Exponential Functions $$e^{y}\left(y^{\prime}+1\right)=1$$

3 step solution

Problem 21

Using the given boundary condition, find the particular solution to each differential equation. $$y=\left(3 y^{3}+x\right) \frac{d y}{d x}, x=1 \text { when } y=1$$

6 step solution

Problem 21

$$y^{\prime}+y=\sin x$$

8 step solution

Problem 21

With Exponential Functions $$e^{x-y} d x+e^{y-x} d y=0$$

6 step solution

Problem 22

Using the given boundary condition, find the particular solution to each differential equation. $$4 x^{2}=-2 y-2 x y^{\prime}, x=5 \text { when } y=2$$

9 step solution

Problem 22

$$y^{\prime}+2 x y=2 x \cos x^{2}$$

7 step solution

Problem 23

Using the given boundary condition, find the particular solution to each differential equation. $$4 x^{2}=-2 y-2 x y^{\prime}, x=5 \text { when } y=2$$

8 step solution

Problem 23

$$y^{\prime}=2 \cos x-y$$

7 step solution

Problem 24

Using the given boundary condition, find the particular solution to each differential equation. $$5 x=2 y^{2}+4 x y y^{\prime}, x=1 \text { when } y=4$$

5 step solution

Problem 24

$$y^{\prime}=\sec x-y \cot x$$

7 step solution

Problem 24

With Trigonometric Functions $$\tan y d x+\tan x d y=0$$

9 step solution

Problem 25

Bernoulli's Equation. $$y^{\prime}+\frac{y}{x}=3 x^{2} y^{2}$$

7 step solution

Problem 25

With Trigonometric Functions $$\cos x \sin y d y+\sin x \cos y d x=0$$

3 step solution

Problem 26

Bernoulli's Equation. $$x y^{\prime}+x^{2} y^{2}+y=0$$

7 step solution

Problem 27

Bernoulli's Equation. $$y^{\prime}=y-x y^{2}(x+2)$$

7 step solution

Problem 28

Bernoulli's Equation. $$y^{\prime}+2 x y=x e^{-x^{2}} y^{3}$$

6 step solution

Problem 28

Using the given boundary condition, find the particular solution to each differential equation. Try some by calculator. $$x d x=4 y d y, x=5 \text { when } y=2$$

6 step solution

Problem 29

Using the given boundary condition, find the particular solution to each differential equation. Try some by calculator. $$y^{2} y^{\prime}=x^{2}, x=0 \text { when } y=1$$

7 step solution

Problem 30

Using the given boundary condition, find the particular solution to each differential equation. Try some by calculator. $$\sqrt{x^{2}+1} y^{\prime}+3 x y^{2}=0, x=1 \text { when } y=1$$

5 step solution

Problem 31

Using the given boundary condition, find the particular solution to each differential equation. Try some by calculator. $$y^{\prime} \sin y=\cos x, x=\pi / 2 \text { when } y=0$$

6 step solution

Problem 32

Using the given boundary condition, find the particular solution to each differential equation. Try some by calculator. $$x(y+1) y^{\prime}=y(1+x), x=1 \text { when } y=1$$

5 step solution

Problem 33

Using the given boundary condition, find the particular solution to each differential equation. $$y^{\prime}=\tan ^{2} x+y \cot x, x=\frac{\pi}{4} \text { when } y=2$$

8 step solution

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