Answer:
$636.53
Step-by-step explanation:
Tax: 9.75/100 × 579.98
= 56.54805
Total cost = 579.98 + tax
= 636.52805
Answer: Option A. 65 m^2
Solution:
Sides: a=10 m, b=14 m, c=20 m
Area: A=?
A=sqrt [p(p-a)(p-b)(p-c) ]
Semi-perimeter: p=(a+b+c)/2
p=(10 m+14 m+20 m)/2
p=(44 m)/2
p=22 m
A=sqrt [ (22 m)(22 m-10 m)(22 m-14 m)(22 m-20 m)]
A=sqrt [ (22 m)(12 m)(8 m)(2 m) ]
A=sqrt [ 4,224 m^4 ]
A=64.99230723 m^2
A=65 m^2
<em>x</em> ^2 + <em>y</em> ^2 = 9 => <em>y</em> = <em>y(x)</em> = ± √(9 - <em>x</em> ^2)
Each cross section would be a square with side length equal to the vertical distance between the upper and lower semicircles defined by <em>y(x)</em>, which is
√(9 - <em>x</em> ^2) - (- √(9 - <em>x</em> ^2)) = 2 √(9 - <em>x</em> ^2)
The area of each square section is the square of this length,
(2 √(9 - <em>x</em> ^2)) = 4 (9 - <em>x</em> ^2) = 36 - 4<em>x</em> ^2
We get the whole solid for -3 ≤ <em>x</em> ≤ 3, so integrating gives a volume of
