Answer:
cos (
) = 
Decimal value: −0.9238795325...
Step-by-step explanation:
Write,
cos
= cos
= −cos 
Now using half angle formula, cos(x) = 2 cos²(
) − 1, we can write cos
= 2
cos²(
) − 1
This means
+ 1 = 2 cos²(
)
2 cos²(
) = 
cos²(
) = 
cos(
) = 
Simplify,
=
= 
Hence,
cos (
) = −cos (
) = 
Answer:
The answer would be -8R.
I think that is the answer solved...sorry.
For the carpet:
Given:
Area = x^2 + x - 20 ft^2
Length = x+ 5 ft
As a carpet is rectangular, the area is defined as the product of the length and the width. To obtain an expression of the carpet's width, the area is to be divided by the length, which is shown below:
__x_-_4___x + 5|x^2 + x - 20 x^2 + 5x -------- -4x - 20 -4x - 20 -------- 0
Therefore, the expression of width = x - 4.
Applying the value of x = 20 to obtain the measurements of the carpet, we obtain the following:
Width = x - 4 = 20 - 4 = 16ft
Length = x+ 5 = 20 + 5 = 25ft.
Therefore, the carpet is 25ft x 16ft.
For the wall:
The same principles apply to the wall as it is also assumed to be rectangular.
Given:
Area = <span>x^2 + 17x + 30 ft^2
Width = x + 2
To obtain the expression for the wall's length, Area is to be divided by the Width, which is shown below:
__x_+_15______x + 2|x^2 + 17x + 30 x^2 + 2x -------- 15x + 30 15x + 30 --------- 0
Therefore, the expression for the wall's length is x + 15.
Applying the value of x = 20 to obtain the wall's dimensions:
Length = x + 15 = 20 + 15 = 35ft.
Width = x + 2 = 20 + 2 = 22ft.
Therefore the wall has measurements of 35ft x 22ft.</span>
Answer:
x+y=4
Step-by-step explanation:
No solution means that the lines will never intersect. We know that the slope of line A is -1, and it's y intercept is 2. If you look at the last option for the answer choices, it's slope is also -1, but it's y intercept is at 4. These lines have the same slope, also known as parallel, so they will never intersect, thus giving no solution