Answer:
Cos(2115°) =1/√2
Sin(2115°) = -1/√2
Step-by-step explanation:
We have to find the values of Cos (2115°) and Sin (2115°).
Now, 2115° can be written as (23×90°+ 45°).
Therefore, the angle 2115° lies in the 4th quadrant where Cos values are positive and Sin values are negative.
Hence, Cos (2115°) = Cos(23×90° +45°) =Sin 45° {Since 23 is an odd number, so the CosФ sign will be changed to SinФ} =1/√2 (Answer)
Again, Sin (2115°) = Sin(23×90° +45°) = -Cos 45° {Since 23 is an odd number, so the SinФ sign will be changed to CosФ} = -1/√2 (Answer)
Now, the required reference angle is 45°. (Answer)
Using the z-distribution, it is found that the 90% confidence interval is given by: (0.6350, 0.6984).
<h3>What is a confidence interval of proportions?</h3>
A confidence interval of proportions is given by:

In which:
is the sample proportion.
In this problem, we have a 90% confidence level, hence
, z is the value of Z that has a p-value of
, so the critical value is z = 1.645.
The sample size and the estimate are given by:

Hence, the bounds of the interval are given by:


The 90% confidence interval is given by: (0.6350, 0.6984).
More can be learned about the z-distribution at brainly.com/question/25890103
#SPJ1
This question boils down to this:
"What is the diagonal of a square with a side length of 90 ft?"
The key to this question is the properties of squares.
All of the angles in a square are right, (90°) but that diagonal is going to bisect two of those into 45° angles.
Now we have two triangles, each with angle measures of 45°, 45°. and 90°.
(an isoceles right triangle)
This 45-45-90 tirnalge is one of two special triangles (the other being the 30-60-90) and here is its special property: the sides opposite these angles can be put as x, x, and x√2 respectively. Why? Well, we know that our triangle is isoceles (the congruent base angles ⇔ congruent sides) and so we call those x...by the Pythagorean theorem...a² + b² = c²...2x² = c²...x√2 = c!
In our case here, that diagonal, being the hypotenuse of our triangle, is going to be 90√2 feet, or approximately 127.3 feet.
The percent discount was,
55.5556. It could be changed to 56%, but as a whole it would more than likely be 55%.
-Mabel <3
If the circumference of a circle is 40 m, its area is 127.32395447352 m².