A 99% confidence interval for the actual mean noise level in hospitals is
1 answer:
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Answer:
A and E
Step-by-step explanation:
Given
20x² - 26x + 8 = 0 ( divide through by 2 )
10x² - 13x + 4 = 0
Consider the factors of the product of the coefficient of the x² term and the constant term which sum to give the coefficient of the x- term.
product = 10 × 4 = 40 and sum = - 13
The factors are - 5 and - 8
Use these factors to split the x- term
10x² - 5x - 8x + 4 = 0 ( factor the first/second and third/fourth terms )
5x(2x - 1) - 4(2x - 1) = 0 ← factor out (2x - 1) from each term
(2x - 1)(5x - 4) = 0
Equate each factor to zero and solve for x
2x - 1 = 0 ⇒ 2x = 1 ⇒ x = → E
5x - 4 = 0 ⇒ 5x = 4 ⇒ x = → A
Now, the cosecant of θ is -6, or namely -6/1.
however, the cosecant is really the hypotenuse/opposite, but the hypotenuse is never negative, since is just a distance unit from the center of the circle, so in the fraction -6/1, the negative must be the 1, or 6/-1 then.
we know the cosine is positive, and we know the opposite side is -1, or negative, the only happens in the IV quadrant, so θ is in the IV quadrant, now
recall that
therefore, let's just plug that on the remaining ones,
now, let's rationalize the denominator on tangent and secant,
however, the cosecant is really the hypotenuse/opposite, but the hypotenuse is never negative, since is just a distance unit from the center of the circle, so in the fraction -6/1, the negative must be the 1, or 6/-1 then.
we know the cosine is positive, and we know the opposite side is -1, or negative, the only happens in the IV quadrant, so θ is in the IV quadrant, now
recall that
therefore, let's just plug that on the remaining ones,
now, let's rationalize the denominator on tangent and secant,