Answer:
Step-by-step explanation:
whole number No
integer No
rational
: No, because pi is irrational.
irrational: YES. π/2 is the ratio of pi to 2, BUT pi is irrational.
Answer:
Option D
and 
Step-by-step explanation:
step 1
<u>Find the equation of the inequality A</u>
we know that
The solution of the inequality A (dashed line) is the shaded area below the dashed line
The equation of the dashed line is 
therefore
The equation of the inequality A is 
step 2
<u>Find the equation of the inequality B</u>
we know that
The solution of the inequality B (solid line) is the shaded area below the solid line
The equation of the solid line is 
therefore
The equation of the inequality B is 
The system of linear inequalities is
and 
Answer:
We need to take the diameter and divide by 2 to find the radius
Step-by-step explanation:
The volume of a sphere is found by
V = 4/3 pi r^3
So we need the radius
We know the diameter
r = d/2
We need to take the diameter and divide by 2
Answer:
The 90% confidence interval for population mean is 
Step-by-step explanation:
From the question we are told that
The sample mean is 
The confidence level is 
The sample size is 
The standard deviation
Now given that the confidence level is 0.90 the level of significance is mathematically evaluated as


Next we obtain the critical value of
from the standardized normal distribution table. The values is 
The reason we are obtaining critical values for
instead of that of
is because
represents the area under the normal curve where the confidence level 1 -
(90%) did not cover which include both the left and right tail while
is just considering the area of one tail which is what we required calculate the margin of error
Generally the margin of error is mathematically evaluated as

substituting values


The 90% confidence level interval is mathematically represented as

substituting values



Answer:
45.40
Step-by-step explanation:
First of all, the shape of rope is not a parabola but a catenary, and all catenaries are similar, defined by:
y=acoshxa
You just have to figure out where the origin is (see picture). The hight of the lowest point on the rope is 20 and the pole is 50 meters high. So the end point must be a+(50−20) above the x-axis. In other words (d/2,a+30) must be a point on the catenary:
a+30=acoshd2a(1)
The lenght of the catenary is given by the following formula (which can be proved easily):
s=asinhx2a−asinhx1a
where x1,x2 are x-cooridanates of ending points. In our case:
80=2asinhd2a
40=asinhd2a(2)
You have to solve the system of two equations, (1) and (2), with two unknowns (a,d). It's fairly straightforward.
Square (1) and (2) and subtract. You will get:
(a+30)2−402=a2
Calculate a from this equation, replace that value into (1) or (2) to evaluate d.
My calculation:
a=353≈11.67
d=703arccosh257≈45.40