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3 years ago

10

How do u get straight A’s?

2 answers:

tatiyna3 years ago

7 0

YOU

GOTTA

GET

SCHOOLED!

Roman55 [17]3 years ago

4 0

Study hard and don't let any thing distract you from your goal

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2m-1-5m+4 what is the answer?

KiRa [710]

$2m-1-5m+4$

$(2m-5m)-1+4

 
$ $Gather \ like \ terms$

$-3m-1+4$

$-3m+3$

8 0

3 years ago

To make green paint students mixed yellow paint with blue paint the table below shows how many yellow and blue drops from a drop

Airida [17]

Answer:

ans is 7

hope it helps !

...

7 0

3 years ago

Emma has 7 bottles: 3 bottles that contain juice, 2 bottles

UNO [17]

Answer: Out of 7 bottles, 2 bottles contain soda. This means that 2 bottles= 29% out of 100%. 7/2 (7 divided by 2) = 0.285. 0.285 can be rounded up to 0.29, meaning that the approximate percentage of the bottles that contain soda is 29%.

4 0

3 years ago

Apply the method of undetermined coefficients to find a particular solution to the following system.wing system.

jarptica [38.1K]

$y''-y'+y=\sin x$

The corresponding homogeneous ODE has characteristic equation $r^2-r+1=0$ with roots at $r=\dfrac{1\pm\sqrt3}2$ , thus admitting the characteristic solution

$y_c=C_1e^x\cos\dfrac{\sqrt3}2x+C_2e^x\sin\dfrac{\sqrt3}2x$

For the particular solution, assume one of the form

$y_p=a\sin x+b\cos x$

${y_p}'=a\cos x-b\sin x$

${y_p}''=-a\sin x-b\cos x$

Substituting into the ODE gives

$(-a\sin x-b\cos x)-(a\cos x-b\sin x)+(a\sin x+b\cos x)=\sin x$

$-b\cos x+a\sin x=\sin x$

$\implies a=1,b=0$

Then the general solution to this ODE is

$\boxed{y(x)=C_1e^x\cos\dfrac{\sqrt3}2x+C_2e^x\sin\dfrac{\sqrt3}2x+\sin x}$

$y''-3y'+2y=e^x\sin x$

$\implies r^2-3r+2=(r-1)(r-2)=0\implies r=1,r=2$

$\implies y_c=C_1e^x+C_2e^{2x}$

Assume a solution of the form

$y_p=e^x(a\sin x+b\cos x)$

${y_p}'=e^x((a+b)\cos x+(a-b)\sin x)$

${y_p}''=2e^x(a\cos x-b\sin x)$

Substituting into the ODE gives

$2e^x(a\cos x-b\sin x)-3e^x((a+b)\cos x+(a-b)\sin x)+2e^x(a\sin x+b\cos x)=e^x\sin x$

$-e^x((a+b)\cos x+(a-b)\sin x)=e^x\sin x$

$\implies\begin{cases}-a-b=0\\-a+b=1\end{cases}\implies a=-\dfrac12,b=\dfrac12$

so the solution is

$\boxed{y(x)=C_1e^x+C_2e^{2x}-\dfrac{e^x}2(\sin x-\cos x)}$

$y''+y=x\cos(2x)$

$r^2+1=0\implies r=\pm i$

$\implies y_c=C_1\cos x+C_2\sin x$

Assume a solution of the form

$y_p=(ax+b)\cos(2x)+(cx+d)\sin(2x)$

${y_p}''=-4(ax+b-c)\cos(2x)-4(cx+a+d)\sin(2x)$

Substituting into the ODE gives

$(-4(ax+b-c)\cos(2x)-4(cx+a+d)\sin(2x))+((ax+b)\cos(2x)+(cx+d)\sin(2x))=x\cos(2x)$

$-(3ax+3b-4c)\cos(2x)-(3cx+3d+4a)\sin(2x)=x\cos(2x)$

$\implies\begin{cases}-3a=1\\-3b+4c=0\\-3c=0\\-4a-3d=0\end{cases}\implies a=-\dfrac13,b=c=0,d=\dfrac49$

so the solution is

$\boxed{y(x)=C_1\cos x+C_2\sin x-\dfrac13x\cos(2x)+\dfrac49\sin(2x)}$

7 0

3 years ago

Find the measurement of angle A

yaroslaw [1]

Answer:

The value of A is 20

Step-by-step explanation:

To find the answer, note that all triangles have a interior degree measurement of 180. Set the sum of the angles equal to 180.

71x - 1 + 20x + 90 = 180

91x + 89 = 180

91x = 91

x = 1

Now we can use this in the A angle to find the value.

A = 20x

A = 20(1)

A = 20

6 0

3 years ago