Hello,
Use the factoration
a^2 - b^2 = (a - b)(a + b)
Then,
x^2 - 81 = x^2 - 9^2
x^2 - 9^2 = ( x - 9).(x + 9)
Then,
Lim (x^2- 81) /(x+9)
= Lim (x -9)(x+9)/(x+9)
Simplity x + 9
Lim (x -9)
Now replace x = -9
Lim ( -9 -9)
Lim -18 = -18
_______________
The second method without using factorization would be to calculate the limit by the hospital rule.
Lim f(x)/g(x) = lim f(x)'/g(x)'
Where,
f(x)' and g(x)' are the derivates.
Let f(x) = x^2 -81
f(x)' = 2x + 0
f(x)' = 2x
Let g(x) = x +9
g(x)' = 1 + 0
g(x)' = 1
Then the Lim stay:
Lim (x^2 -81)/(x+9) = Lim 2x /1
Now replace x = -9
Lim 2×-9 = Lim -18
= -18
Answer:
We need a sample size of at least 657.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence level of 
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of 
.
The margin of error is given by:
45 percent of its claims have errors.
So 
99% confidence level
So 
, z is the value of Z that has a pvalue of 
, so 
.
What sample size is needed if they wish to be within 5 percent of the actual
This is a sample size of at least n, in which n is found when M = 0.05.
We need a sample size of at least 657.
Answer:
<h3>19,133.067</h3>
Step-by-step explanation:
Volume of the ball (spherical in nature) Vb = 4/3πrb³
Volume of the hole Vh = 4/3πrh³
rb is the radius of the ball
rh is the radius of the hole
If a ball of radius 17 has a round hole of radius 7 drilled through its center, the volume of the resulting solid will be expressed as:
V = Vb - Vh
V = 4/3πrb³ - 4/3πrh³
factor out the like terms;
V = 4/3π(rb³-rh³)
Given
rb = 17
rh = 7
V = 4/3π(17³-7³)
V = 4/3π(4913-343)
V = 4/3π(4570)
V = (4π*4570)/3
V = 57,399.2/3
V = 19,133.067
Hence the volume of the resulting solid is 19,133.067
I think it is 10 feet. I used the Pythagorean Theorem. a2+b2=c2 6^2 + 8^2 = c^2. 36+64= c^2. 100 = c ^2. 10 = c.
