Answer:
c=80
Step-by-step explanation:
Based on my reading the critical damping occurs when the discriminant of the quadratic characteristic equation is 0.
So let's see that characteristic equation:
20r^2+cr+80=0
The discriminant can be found by calculating b^2-4aC of ar^2+br+C=0.
a=20
b=c
C=80
c^2-4(20)(80)
We want this to be 0.
c^2-4(20)(80)=0
Simplify:
c^2-6400=0
Add 6400 on both sides:
c^2=6400
Take square root of both sides:
c=80 or c=-80
Based on further reading damping equations in form
ay′′+by′+Cy=0
should have positive coefficients with b also having the possibility of being zero.
Answer:
Tests is 100% Accurate, so by using the formula of random variable probability.
Step-by-step explanation:
Total number of people = 10
Sample space = p(A) = 10
Number of people that have flu = n(s) = 4
Pick random 3 persons, the possibility that they have flue is n(A) = ?
Let X is the random variable, consisting of number of positive flu test,
Tests is 100% Accurate, so by using the formula of random variable probability, we get
P(X) = n (A) / n(S)
P(X) = ¾, is the probability of having positive flu test
Answer:
-5x+ -35y
Step-by-step explanation:
-5x+ -35y
