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3 years ago

How can you use a compatible number to estimate a quotient when dividing a decimal by a whole number?

Mathematics

2 answers:

8090 [49]3 years ago

5 0

Answer: just follow these simple steps!

Step-by-step explanation:

1. Estimate the quotient.

2. Perform the division. Remember to place a zero in the quotient when the divisor is larger than the dividend. ...

3. Compare your estimate with your quotient to verify that the answer makes sense.

olga2289 [7]3 years ago

4 0

A compatible number is going to give you a answer relatively close to your answer.

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The distribution of the heights of students in a large class is roughly Normal. Moreover, the mean height is 68 inches, and appr

Thepotemich [5.8K]

Answer:

Probably equal to 6 or 7.

Step-by-step explanation:

3 0

3 years ago

Solve the following differential equation using using characteristic equation using Laplace Transform i. ii y" +y sin 2t, y(0) 2

kifflom [539]

Answer:

The solution of the differential equation is $y(t)= - \frac{1}{3} Sin(2t)+2 Cos(t)+\frac{5}{3} Sin(t)$

Step-by-step explanation:

The differential equation is given by: y" + y = Sin(2t)

<u>i) Using characteristic equation:</u>

The characteristic equation method assumes that y(t)= $e^{rt}$ , where "r" is a constant.

We find the solution of the homogeneus differential equation:

y" + y = 0

$y'=re^{rt}$

$y"=r^{2}e^{rt}$

$r^{2}e^{rt}+e^{rt}=0$

$(r^{2}+1)e^{rt}=0$

As $e^{rt}$ could never be zero, the term (r²+1) must be zero:

(r²+1)=0

r=±i

The solution of the homogeneus differential equation is:

$y(t)_{h}=c_{1}e^{it}+c_{2}e^{-it}$

Using Euler's formula:

$y(t)_{h}=c_{1}[Sin(t)+iCos(t)]+c_{2}[Sin(t)-iCos(t)]$

$y(t)_{h}=(c_{1}+c_{2})Sin(t)+(c_{1}-c_{2})iCos(t)$

$y(t)_{h}=C_{1}Sin(t)+C_{2}Cos(t)$

The particular solution of the differential equation is given by:

$y(t)_{p}=ASin(2t)+BCos(2t)$

$y'(t)_{p}=2ACos(2t)-2BSin(2t)$

$y''(t)_{p}=-4ASin(2t)-4BCos(2t)$

So we use these derivatives in the differential equation:

$-4ASin(2t)-4BCos(2t)+ASin(2t)+BCos(2t)=Sin(2t)$

$-3ASin(2t)-3BCos(2t)=Sin(2t)$

As there is not a term for Cos(2t), B is equal to 0.

So the value A=-1/3

The solution is the sum of the particular function and the homogeneous function:

$y(t)= - \frac{1}{3} Sin(2t) + C_{1} Sin(t) + C_{2} Cos(t)$

Using the initial conditions we can check that C1=5/3 and C2=2

<u>ii) Using Laplace Transform:</u>

To solve the differential equation we use the Laplace transformation in both members:

ℒ[y" + y]=ℒ[Sin(2t)]

ℒ[y"]+ℒ[y]=ℒ[Sin(2t)]

By using the Table of Laplace Transform we get:

ℒ[y"]=s²·ℒ[y]-s·y(0)-y'(0)=s²·Y(s) -2s-1

ℒ[y]=Y(s)

ℒ[Sin(2t)]= $\frac{2}{(s^{2}+4)}$

We replace the previous data in the equation:

s²·Y(s) -2s-1+Y(s) = $\frac{2}{(s^{2}+4)}$

(s²+1)·Y(s)-2s-1= $\frac{2}{(s^{2}+4)}$

(s²+1)·Y(s)= $\frac{2}{(s^{2}+4)}+2s+1=\frac{2+2s(s^{2}+4)+s^{2}+4}{(s^{2}+4)}$

Y(s)= $\frac{2+2s(s^{2}+4)+s^{2}+4}{(s^{2}+4)(s^{2}+1)}$

Y(s)= $\frac{2s^{3}+s^{2}+8s+6}{(s^{2}+4)(s^{2}+1)}$

Using partial franction method:

$\frac{2s^{3}+s^{2}+8s+6}{(s^{2}+4)(s^{2}+1)}=\frac{As+B}{s^{2}+4} +\frac{Cs+D}{s^{2}+1}$

2s^{3}+s^{2}+8s+6=(As+B)(s²+1)+(Cs+D)(s²+4)

2s^{3}+s^{2}+8s+6=s³(A+C)+s²(B+D)+s(A+4C)+(B+4D)

We solve the equation system:

A+C=2

B+D=1

A+4C=8

B+4D=6

The solutions are:

A=0 ; B= -2/3 ; C=2 ; D=5/3

So,

Y(s)= $\frac{-\frac{2}{3} }{s^{2}+4} +\frac{2s+\frac{5}{3} }{s^{2}+1}$

Y(s)= $-\frac{1}{3} \frac{2}{s^{2}+4} +2\frac{s }{s^{2}+1}+\frac{5}{3}\frac{1}{s^{2}+1}$

By using the inverse of the Laplace transform:

ℒ⁻¹[Y(s)]=ℒ⁻¹[ $-\frac{1}{3} \frac{2}{s^{2}+4}$ ]-ℒ⁻¹[ $2\frac{s }{s^{2}+1}$ ]+ℒ⁻¹[ $\frac{5}{3}\frac{1}{s^{2}+1}$ ]

$y(t)= - \frac{1}{3} Sin(2t)+2 Cos(t)+\frac{5}{3} Sin(t)$

3 0

3 years ago

The perimeter of a triangle is 50 feet. One side of the triangle is 4 times the second side. The third side is 14 feet longer th

shutvik [7]

Idk idk idfk idk idk 124

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4 years ago

Write an equation of the line that passes through (8,1) and is perpendicular to the line 2y+4x=12.

Olegator [25]

Answer:

Step-by-step explanation:

note:when you do perpendicular lines you must change the slope to the oppisite and reciporcal

2y+4x=12

2y-1/4x=12

1/4x+2y=12

3 0

3 years ago

Please help to solve this please with steps.

Blababa [14]

Answer:

284cm^2

Step-by-step explanation:

first, we split up the shape into seperate sections that we can easily find the areas of.

i will draw vertical lines in the bottom left and right, leaving me with 2 seperate rectangles and 1 irregular pentagon.

we know that these rectangles are 4x8cm, so we do 4 * 8 which gives us 32.

there are 2 of these, so 32 x 2 = 64cm^2.

now, i chose to seperarte the pentagon into a rectangle and a triangle,

and i found the height and width of the rectangle to be (18 - (4+4)) x (8+7), or 10 x 15.

the area of the rectangle is 150cm^2.

now, for the triangle.

the line through the centre of th shape is 22cm long, but we only want the part in the triangle. luckily, there are mesurements that can help us with this.

8 + 7 = 15.

22 - 15 = 7.

now we know that the height of the triangle is 7 cm.

from earlier, we also know the base, which is 10cm.

7 x 10 = 70cm^2.

now we add all these together:

70 + 150 + 64 = 284cm^2

4 0

3 years ago