<span>3x''+3x'+7x = 9sin 3t - to begin
then </span>Use the method of undetermined coefficients
![xp=Asin(3t)+Bcos(3t).](https://tex.z-dn.net/?f=xp%3DAsin%283t%29%2BBcos%283t%29.)
Then you need to find <span><span>x′p</span> and <span>x′′p and sub them into equation, that will help you to solve A and B.
</span></span>
![xp=Asin(3t)+Bcos(3t) x'p=3Acos(3t)−3Bsin(3t) x''p=−9Asin(3t)−9Bcos(3t) ](https://tex.z-dn.net/?f=xp%3DAsin%283t%29%2BBcos%283t%29%0A%0Ax%27p%3D3Acos%283t%29%E2%88%923Bsin%283t%29%0A%0Ax%27%27p%3D%E2%88%929Asin%283t%29%E2%88%929Bcos%283t%29%20%0A)
And finally you will have this :
<span><span><span>3<span>x′′</span>+3<span>x′</span>+7x=9sin(3t)</span><span>[−27Asin(3t)−27Bcos(3t)]+[9Acos(3t)−9Bsin(3t)]+[7Asin(3t)+7Bcos(3t)]</span><span>=9sin(3t)</span><span>(−20A+9B)sin(3t)+(−20B+9A)cos(3t)=9sin(3t)</span></span></span>
Answer:
7.75 ft.
Step-by-step explanation:
a^2 + b^2 = c^2
2^2 + b^2 = 8^2
4 + b^2 = 64
64 - 4 = b^2
60 = b^2
b = 7.75
All numbers that round to 80 include...
75, 76, 77, 78, 79, 80, 81, 82, 83, 84
An easy song that can help you remember when to round up or down is this...
(sing to the rhythm of "We Will Rock You")
or you can just read it...
~~~~~~~~~~~~~~~~~~~~~~~
Find your place, look next door
5 or greater add one more
All digits in front, stay the same
All digits behind, zero's your name
(optional)
We will, we will round you
~~~~~~~~~~~~~~~~~~~~~~~
Some examples of rounding to the nearest tens place would include...
93 -> 90
54 -> 50
98 -> 100
22 -> 20
167 -> 170
Answer option : C
explanstion: count all of the variables in the equation, then multiply x times the number of variables