By using what we know about right triangles, we conclude that the height is 11ft.
<h3>
How far is the top of the escalator from the ground floor? </h3>
We can think of this as a right triangle.
Where the length of the escalator is the hypotenuse
We know that the angle of depression is 42.51°, then the top angle of our right triangle is:
90° - 42.51° = 47.49°
Now, the height of the top of the escalator would be the adjacent cathetus to said angle, then we can use the relation:
cos(a) = (adjacent cathetus)/(hypotenuse)
Replacing what we know:
cos(47.49°) = height/16ft
cos(47.49°) *16ft = height = 10.8ft
Rounding to the nearest foot, we get:
height = 11ft
If you want to learn more about right triangles:
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For this case we have the following arithmetic sequence:

To write in function form, we apply distributive property to the terms within parentheses:

Different signs are subtracted and the major sign is placed.
We simplify:

Answer:

Option C
The complete factorization of the equation 81x² - 100 is; (9x - 10)(9x + 10)
<h3>How to factorize quadratic equations?</h3>
We are given the quadratic equation;
81x² - 100
Now, according to quadratic identities, we know that;
(a + b) * (a - b) = a² - b²
Now, our equation can also be expressed as;
81x² - 100 = 9²x² - 10²
Thus, applying the quadratic identity gives us;
(9x + 10)(9x - 10)
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Answer:
3^-1 > 1/4
Step-by-step explanation:
3^-1 = 1/3
1/4 = 1/4
1/3 = 0.3333
1/4 = 0.25
0.3333>0.25
3^-1 > 1/4
Answer: 13 groups
Step-by-step explanation:
78/6 = 13