9514 1404 393
Answer:
6 feet
Step-by-step explanation:
The volume of a cylinder is given by ...
V = πr^2·h
For a sphere, the volume is ...
V = 4/3πr^3
You want the volumes to be the same when h=8, so we have ...
πr^2·8 = 4/3πr^3
Dividing by πr^2, we have ...
8 = 4/3r
r = 3/4·8 = 6
The radius is 6 feet.
Answer:
the answer will be verified by an expert. Until then, talk to a tutor.
the picture in the attached figure
we know that
area of the triangle is equal to

in this problem
A=47 in²
b=x
h=x
so

therefore
the answer is
x=9.7 in
Answer:
I think it is $156
Step-by-step explanation:
Multiply the numbers
The function, as presented here, is ambiguous in terms of what's being deivded by what. For the sake of example, I will assume that you meant
3x+5a
<span> f(x)= ------------
</span> x^2-a^2
You are saying that the derivative of this function is 0 when x=12. Let's differentiate f(x) with respect to x and then let x = 12:
(x^2-a^2)(3) -(3x+5a)(2x)
f '(x) = ------------------------------------- = 0 when x = 12
[x^2-a^2]^2
(144-a^2)(3) - (36+5a)(24)
------------------------------------ = 0
[ ]^2
Simplifying,
(144-a^2) - 8(36+5a) = 0
144 - a^2 - 288 - 40a = 0
This can be rewritten as a quadratic in standard form:
-a^2 - 40a - 144 = 0, or a^2 + 40a + 144 = 0.
Solve for a by completing the square:
a^2 + 40a + 20^2 - 20^2 + 144 = 0
(a+20)^2 = 400 - 144 = 156
Then a+20 = sqrt[6(26)] = sqrt[6(2)(13)] = 4(3)(13)= 2sqrt(39)
Finally, a = -20 plus or minus 2sqrt(39)
You must check both answers by subst. into the original equation. Only if the result(s) is(are) true is your solution (value of a) correct.