The first one is of order 5, so it has either 1, 3 or 5 real roots (unless any coefficent was complex). Proof complete :)
The other one, if it has a solution, it must be in [-1;1]. Because it only gives positive results the solution is further restricted to [0;1]. Because the cosine function is continuous and strictly decreasing on this interval, the difference of x and it's cosine will shrink up to some point within the interval where it gets to 0 (the solution) and then flips sign (the cosine gets less than the number), further decreasing until the end of the interval.
Answer:
is there a graph for this that I can see?
The mean ( average ) is given as 1200 hours.
The standard deviation is 200, sample size is 100.
Find the standard error:
√(200^2 / 100) = 20
Now calculate the confidence interval. For 95% the Z number is 1.96
Multiply Z by the standard error:
1.96 x 20 =39.2
Now find the range that the mean should be within:
1200 - 39.2 = 1160.8
1200 + 39.2 = 1239.2
The samples should be between 1160.8 and 1239.2 for a 95% confidence interval.
Since the average was 1050, which is below 1160.8 the bulbs are not in compliance.
Answer:
34
Step-by-step explanation:
Points B,C,D, and E are points on the edge of the circle.
and
are in the same segment.
We have that: 
We want find 
Recall that angles in the same segment are congruent.

So the answer is 34