Evaluate the expression.<br><br> (65+ (1/5 x 5) + 6) Divided by 9

All of these ODEs model a system with a spring, mass and dashpot.

Wewaii [24]

Answer:

− 3 y ' ' − 3 y ' + 3 y = 0 : over-damped

− 2 y ' ' − 4 y ' + 1 y = 0 : over-damped

1 y ' ' + 7 y ' + 5 y = 0: over-damped

Step-by-step explanation:

Using the characteristic equation you can express a differential equation of order n as an algebraic equation of degree n:

$a_ny^n+a_n_-_1y^{n-1}+...+a_1y'+a_oy=0$

This differential equation will have a characteristic equation of the form:

$a_nr^n+a_n_-_1r^{n-1}+...+a_1r+a_o=0$

Now, you can classify the solution for a differential equation using a simple method. In order to do it, you just need to use the discriminant.

If the discriminant is greater than zero, the solution is over-damped

If the discriminant is less than zero, the solution is under-damped

If the discriminant is equal to zero, the solution is critically damped

So, given the differential equation:

$-3y''-3y+3y=0$

Which has characteristic equation of the form:

$-3r^2-3r+3=0$

The quadratic polynomial of the form:

$ar^2+br+c=0$

Has discriminant:

$Disc=b^2-4ac$

In this case:

$a=-3\\b=-3\\c=3$

So:

$Disc=(-3)^2-4(-3)(3)=9-(-36)=45$

In this case:

$Disc=45>0$

Therefore the solution is over-damped.

Now, given the differential equation:

$-2y''-4y'+1y=0$

Which has characteristic equation of the form:

$-2r^2-4r+1=0$

The quadratic polynomial of the form:

$ar^2+br+c=0$

Has discriminant:

$Disc=b^2-4ac$

In this case:

$a=-2\\b=-4\\c=1$

So:

$Disc=(-4)^2-4(-2)(1)=16+8=24$

In this case:

$Disc=24>0$

Therefore the solution is over-damped.

Finally, given the differential equation:

$1y''+7y'+5y=0$

Which has characteristic equation of the form:

$1r^2+7r+5=0$

The quadratic polynomial of the form:

$ar^2+br+c=0$

Has discriminant:

$Disc=b^2-4ac$

In this case:

$a=1\\b=7\\c=5$

So:

$Disc=(7)^2-4(1)(5)=49-20=29$

In this case:

$Disc=29>0$

Therefore the solution is over-damped.

6 0

3 years ago

What is the sum if the first 22 terms of the following series? 86 + 79 + 72 + 65 +58+...

Arturiano [62]

Seems to be an arythmetic sequence
Sn=[n(a1+an)]/2
where
Sn means sum of all terms up the nth term
n=number of terms
a1=first term
an=nth term

so from 86 to the 22th term is from a1 to a22

find teh sequence
miknus 7 each time
an=a1+d(n-1)
an=87-7(n-1)
find 22n term
a22=87-7(22-1)
a22=87-7(21)
a22=87-147
a22=-60

S22=[22(87-60)]/2
S22=[22(27)]/2
S22=594/2
S22=297

the sum is 297

5 0

4 years ago

Convert 22 to a numeral in base 2.

musickatia [10]

The answer is 10110

===============================================

Explanation:

Divide 22 over 2. Use long division to find the quotient and remainder
22/2 = 11 remainder 0 <<--- this remainder will be used later. Call it A, so A = 0

Now repeat for the value 11, which was the quotient above
11/2 = 5 remainder 1 <<--- this remainder will be used later. Call it B, so B = 1

Repeat again for the quotient we just got
5/2 = 2 remainder 1 <<--- this remainder will be used later. Call it C, so C = 1

Repeat again
2/2 = 1 remainder 0 <<--- this remainder will be used later. Call it D, so D = 0

Repeat again
1/2 = 0 remainder 1 <<--- this remainder will be used later. Call it E, so E = 1

The last quotient above is 0, so we stop here. If we tried to keep going, then we'd get nothing but 0 remainders forever.

The remainders we got above were:
A = 0
B = 1
C = 1
D = 0
E = 1

The idea is to read the remainders in reverse order in which we found. So we start with E and work back to A
E = 1
D = 0
C = 1
B = 1
A = 0

So 22 base 10 = 10110 base 2

5 0

3 years ago

Read 2 more answers

what is the unit rate of 3 pizzas for $19.99 and round the answer to nearest hundredth ? PLZzz HELP ASAP!!!!

kipiarov [429]

Divide 19.99 / 3

Get 6.663

Round to 6.66

Unit rate for 3 pizzas at 19.99 is 6.66

4 0

4 years ago

Jack is trying to make extra money on his summer vacation from school. He works two different jobs, earning $9 per hour washing