That bracket symbol, with an r in it, means "the absolute value of r".
So r's absolute value is -2 meaning r is two units from zero
r= 2
Answer: y = 6 mi. .
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Explanation:
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Area of a triangle = (½) * (base) * (height) ;
or, A = (½) * b * h ; or, A = b*h / 2 ;
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Given: A = 24.3 mi ² ;
b = 8.1 mi
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Find the height, "h" ; (in units of "miles", or , "mi" ).
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Plug in the known values into the formula:
24.3 mi ² = (½) * (8.1 mi) *(h) ;
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Solve for "h" (height) ;
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(½) * (8.1 mi) = 4.05 mi ;
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Rewrite:
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24.3 mi² = (4.05 mi) *(h) ; Solve for "h" ;
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Divide each side of the equation by "(4.05 mi)" ; to isolate "h" on one side of the equation ; and to solve for "h" ;
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24.3 mi² / 4.05 mi = (4.05 mi) *(h) / 4.05 mi ;
→ 6 mi = h ; ↔ h = 6 mi.
→ h = y = 6 mi.
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The function
... f(x) = (x+2)/(x-1) = 1 + 3/(x-1)
is symmetrical about the line y=x, hence is its own inverse.
We can evaluate the desired derivative directly.
... f'(x) -3/(x-1)²
so f'(2) is
... f'(2) = -3/(2-1)²
