See here: https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:quadratic-functions-equations/x2f8bb11595b61c86:quadratic-formula-a1/a/quadratic-formula-proof-review
Note that i is additionally the index of the summation.
Binomial theorem expansion so we have \(\sum _{i=0}^4\binom{4}{i}\cdot \:1^{\left(4-i\right)}i^i=1+4i-6-4i+1=\boxed{-4}~~\blacksquare\)
Another way would be to evaluate \(|-2-2i\sqrt 3|^3\). We have: \(\sqrt{(-2)^2+(-2\sqrt 3)^2}=\sqrt{4+4\cdot 3}=\sqrt{16}=4\implies 4^3=\boxed{64}~~\blacksquare\)
Sorry that's wrong. It should like this: cos^2 0+cos^2 1+cos^2 2 ... cos^2 90 (in degrees). heureka was correct
Thanks, CPhill! :)
If measurement of angle ABC=75 degrees, then how many segments will he draw until he reaches his starting point A.
It's supposed to say "If
Thank you :)
+142 
