Answer:
2
Step-by-step explanation:
f(x)=2x^2+9x-5
When we are find how many times it intersects the x axis, we are finding the zero's. Set the equation equal to zero
0=2x^2+9x-5
Factor the equation
0 = (2x+1) (x-5)
2*1
1*-5 = -5
2*-5 +1*1 = -9
This checks for the first last and middle terms so we factored correctly
Then using the zero product property
2x+1 = 0 and x-5 =0
2x = -1 x=5
x = -1/2 and x=5
This function crosses the x axis 2 times
Answer:
538 books should be tested.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so 
Now, find the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.
How many books should be tested to estimate the average force required to break the binding to within 0.08 lb with 99% confidence?
n books should be tested.
n is found when 
We have that 






Rounding up
538 books should be tested.
Y is increased by 6 because if you imagine x being 3 then y would = 16 but if you increase x by 3 making 6 then y would = 22 and 16 increased by 6 is 22