The empirical rule tells you 68% of normally-distributed observations are within 1 standard deviation of the mean.
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This is a number you may want to memorize, along with the numbers for 2 (95%) and 3 (99.7%) standard deviations.
The given <span>polynomial is ⇒⇒⇒ </span><span>f(x) = x³ - 3x² + 81x - 243
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by factoring the absolute term (243) to find one of the factors of the the polynomial
∴ 243 = (1 * 243) or (3 * 81) or (9 * 27)
check which of the numbers {1 , 3 , 9 , 27 , 81 , 243} make f(x)<span>= 0
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i have checked 3 and it makes <span>polynomial = 0
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i.e: f(3) = 0 ⇒⇒ (x - 3) is one of the factors of f(x)
By using the reminder theorem ⇒⇒ see the attache figure
∴

And ⇒⇒ (x² + 81) is a sum of two squares which can be factored using the complex numbers as following
x² + 81 = ( x + 9i ) ( x - 9i )
∴ f(x) = <span>
x³ - 3x² + 81x - 243 = (x - 3)(x + 9i)(x - 9i)</span>
Here is the solution based on the given problem above.
Given: Area of the piece of paper = 84 square inches
Width = 10 1/2 or 10.5 inches long
? = length of the piece of paper
To find the area of an object, the formula would be A= L x W
Now, let's substitute the given values above
84in2 = L(10.5in)
Now, divide both sides with 10.5 and we get 8.
L = 8 inches.
Therefore, the length of the paper is 8 inches.
Hope this solution helps.
A is (-1,0) B is (0,-3) C is line of symmetry D is (3,0) E is (2,-3) F is (1, -4)