Help help plz help plz i will put u breanliest

The floor of a skating rink is circular and has a radius of 14 meters. What is the

Lerok [7]

Answer:

Step-by-step explanation:

615.75m squared

4 0

3 years ago

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Set up but do not solve for the appropriate particular solution yp for the differential equation y′′+4y=5xcos(2x) using the Meth

taurus [48]

Answer:

So, solution of the differential equation is

$y(t)=-\frac{5x^2}{4}\cot 2x\cdot \cos 2x+c_1e^{-2it}+c_2e^{2it}\\$

Step-by-step explanation:

We have the given differential equation: y′′+4y=5xcos(2x)

We use the Method of Undetermined Coefficients.

We first solve the homogeneous differential equation y′′+4y=0.

$y''+4y=0\\\\r^2+4=0\\\\r=\pm2i\\\\$

It is a homogeneous solution:

$y_h(t)=c_1e^{-2i t}+c_2e^{2i t}$

Now, we finding a particular solution.

$y_p(t)=A5x\cos 2x\\\\y'_p(t)=A5\cos 2x-A10x\sin 2x\\\\y''_p(t)=-A20\sin 2x-A20x\cos 2x\\\\\\\implies y''+4y=5x\cos 2x\\\\-A20\sin 2x-A20x\cos 2x+4\cdot A5x\cos 2x=5x\cos 2x\\\\-A20\sin 2x=5x\cos 2x\\\\A=-\frac{x}{4} \cot 2x\\$

we get

$y_p(t)=A5\cos 2x\\\\y_p(t)=-\frac{5x^2}{4}\cot 2x\cdot \cos 2x\\\\\\y(t)=y_p(t)+y_h(t)\\\\y(t)=-\frac{5x^2}{4}\cot 2x\cdot \cos 2x+c_1e^{-2it}+c_2e^{2it}\\$

So, solution of the differential equation is

$y(t)=-\frac{5x^2}{4}\cot 2x\cdot \cos 2x+c_1e^{-2it}+c_2e^{2it}\\$

7 0

3 years ago

QUICKK ANSWERR (will mark brainlist)

atroni [7]

Answer:

Jessie sold x DVDs for $<u>3</u> each and then sold a board game for $<u>12</u>. Jessie made (select) $27 in her sales. How many DVDs did she sell?

She sold 5 DVDs

Step-by-step explanation:

3x+12=27

3x=15

x=5

5 DVDS

4 0

3 years ago

There are 4 times as many monkeys as elephants at the zoo. If the totAl number of monkeys and elephants is 35, how many monkeys

Tanya [424]

Let's call the number of elephants x.
x+4x=35
5x=35
x=7
So there are 7 elephants. There are four times as many monkeys.
7×4=28
There are 28 monkeys.

8 0