I don't mean to be clicking just to get a point without answering the question but there's no comment option.
Is there more to the question, any more info?
Answer:
It returns the angle whose cosine is a given number.
Step-by-step explanation:
For every trigonometry function, there is an inverse function that works in reverse. These inverse functions have the same name but with 'arc' in front. (On some calculators the arccos button may be labeled arccos, or sometimes cos-1.) So the inverse of cos is arccos etc. When we see "arccos x", we understand it as "the angle whose cosine is x"
cos30 = 0.866 Means: The cosine of 30 degrees is 0.866
arccos 0.866 = 30 Means: The angle whose cosine is 0.866 is 30 degrees.
Use arccos when you know the cosine of an angle and want to know the actual angle.
Answer:
Step-by-step explanation:
Rewrite this quadratic in standard form: 3x^2 + 7x - 1.
The coefficients of x are {3, 7, -1}, and so the discriminant is b^2 - 4ac, or
7^2 - 4(3)(-1), or 49 + 12, or 61. Because the discriminant is positive, this quadratic has two real, unequal roots
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Answer:
A = (16π -32) in²
P = (4π +8√2) in
Step-by-step explanation:
The area is that of a quarter-circle of radius 8 inches less half the area of a square with side length 8 inches. Two formulas are useful:
area of a circle = πr² . . . . .r = radius
area of a square = s² . . . . s = side length
Then your area is ...
A = (1/4)π(8 in)² - (1/2)(8 in)² = (64 in²)(π/4 -1/2)
A = (16π -32) in²
____
The applicable formulas for the side lengths of your figure are ...
arc BD = (1/4)(2πr) = π(r/2) = π(8 in)/2 = 4π in
segment BD = (8 in)√2
The perimeter is the sum of these lengths, so is ...
P = (4π +8√2) in
_____
Of course, you are very familiar with the fact that an isosceles right triangle with side lengths 1 has a hypotenuse of length √(1²+1²) = √2. Scaling the triangle by a factor of 8 inches means the segment AB will be 8√2 inches long.