So the best and correct answer is C because this is how you do it The surface area of the cone has formula
pi * radius * ( radius + sqrt ( height^2 + radius^2)) =
pi * radius^2 + pi * radius * sqrt( height^2 + radius^2)
However, this includes the base of the cone and the hats do NOT have
that. "The hats are shaped like a cone with NO BASE", says the 3rd sentence.
So the formula becomes pi * radius * sqrt( height^2 + radius^2)
diameter = 16
radius = 8
height = 9
The surface area of ONE of the hats is pi * 8 * sqrt( 9^2 + 8^2)
= pi * 8 * sqrt( 81+64)
= pi * 8 * sqrt(145)
302.63828053.....
21 of them is 21 * 302... = 6355.40689112841343251026086.....
Answer:
no solution
Step-by-step explanation:
5x - 8(x + 5) = 6 - 3x
Remember to follow PEMDAS. Note the equal sign, what you do to one side, you do to the other.
First, distribute -8 to all terms within the parenthesis
-8(x + 5) = (-8)(x) + (-8)(5) = -8x - 40
5x - 8x - 40 = 6 - 3x
Isolate the variable (x). Add 3x & 40 to both sides
5x - 8x (+3x) - 40 (+40) = 6 (+40) - 3x (+3x)
5x - 8x + 3x = 6 + 40
Simplify. Combine like terms
(5x - 8x + 3x) = (6 + 40)
0 = 46 ; False 0 ≠ 46 ∴ no solution is your answer
~
Cot(3x)=3^(1/2)
cot(x)= cos(x)/sin(x)
cot(3x)= cos(3x)/sin(3x)
look at a unit circle chart
find a value for cos that has sqrt(3) in it
which one will reduce so that the cos/sin will equal sqrt(3)?
pi/6 radians
now cot(3x) implies that x is one third this value
pi/18 is the answer
