<span>What is the edge length of a face-centered cubic unit cell made up of atoms having a radius of 125 pm? </span>393pm
We can't help unless we know what to "rewrite"
Cos(2x) = cos^2(x) - sin^2(x) - cos(x)
but sin^2(x) = 1 - cos^2(x)
cos(2x) - cos(x) = cos^2(x) - (1 - cos^2(x) ) - cos(x)
cos(2x) - cos(x) = cos^2(x) - 1 + cos^2(x) - cos(x)
cos(2x) - cos(x) = 2cos^2(x) - 1 - cos(x)
cos(2x) - cos(x) = (2cos(x) + 1)(cos(x) - 1)
I think this is what you have asked for.
N - the number
14 + n = 17 |subtract 14 from both sides
n = 3
