r = 2 inches
total h of the cylinder = 6+6+6 = 18 inches
cos (2x) = cos x
2 cos^2 x -1 = cos x using the double angle formula
2 cos ^2 x -cos x -1 =0
factor
(2 cos x+1) ( cos x -1) = 0
using the zero product property
2 cos x+1 =0 cos x -1 =0
2 cos x = -1 cos x =1
cos x = -1/2 cos x=1
taking the arccos of each side
arccos cos x = arccos (-1/2) arccos cos x = arccos 1
x = 120 degrees x=-120 degrees x=0
remember you get 2 values ( 2nd and 3rd quadrant)
these are the principal values
now we need to add 360
x = 120+ 360n x=-120+ 360n x = 0 + 360n where n is an integer
You would have to estimate this and a rough estimate would be around 240
The fraction 22/7 has a value of 3.142857, so it has the same first three digits as pi. Both 3.14 and 22/7 are approximations of pi. In fact, 22/7 is close to pi than 3.14 is. Pi is irrational. That is, the decimal expansion never ends and never repeats, so any number of decimal places we wrote out is an approximation. The approximation 3.14 is about 1/2 percent off from the true value, and the fairly well know 3.141559 is within 0.000084 percent.
Answer:
Step-by-step explanation:
Let age of each twin be x
let age of sister be s
So we can write:
x + 4 = s
The product of the 3 siblings ages is 3482 more than sum. We can write:
This can be simplified as:
We replace s with "x + 4" and solve:
<u>Note:</u> To solve this cubic, we used technology
Thus, we can say the twins are 14 years old
