Answer:

Step-by-step explanation:
The cotangent function can be rewritten by trigonometric relations, that is:
(1)
By taking approach the periodicity properties of the cosine and sine function (both functions have a period of 360°), we use the following equivalencies:
(2)
(3)
By (2) and (3) in (1), we have following expression:

If we know that
and
, then the result of the trigonometric expression is:


Answer:
Measure of ∠A = 60.07°
Step-by-step explanation:
From the figure attached,
ΔABC is a right triangle,
Measure of side AC = 15 units
and measure of side BC = 13 units
By applying Sine rule in this triangle,
SinA = 
Opposite side of angle A = Side AC
and hypotenuse of the triangle = Side BC
SinA = 
A =
A = 60.07°
Therefore, measure of angle A is 60.07°.
<h3>
Answer: 40</h3>
========================================================
Explanation:
The old dimensions of the rectangle were 30 by 15.
The new dimensions are 30+x by 15+x, where x is some positive number.
The new rectangle dimensions multiply to 1000
(30+x)(15+x) = 1000
Use the FOIL rule to expand out the left side like so
(30+x)(15+x) = 1000
450+30x+15x+x^2 = 1000
450+45x+x^2 = 1000
x^2+45x+450
Then lets get everything to one side
x^2+45x+450 = 1000
x^2+45x+450-1000 = 0
x^2+45x-550 = 0
---------------------
From here we use the quadratic formula
Plug in a = 1, b = 45, and c = -550.


Earlier we defined x to be a positive number. This means we ignore x = -55. It makes no sense to add on a negative amount to each dimension.
The only practical answer is x = 10.
So each dimension is increased by 10 feet.
--------------------------
If x = 10, then the old dimensions of 30 by 15 bump up to 30+10 = 40 by 15+10 = 25
Then note how 40*25 = 1000, which helps confirm we have the correct dimensions.
--------------------------
Now go back to the question at hand: we want to find the new width. The old width was 30 feet. The new width is 30+x = 30+10 = 40 feet
Answer:
A(2)= 18, A(4)= 40, A(11)= 117