Was nick's work correct? and if not, why?

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.

Hey free points ! people i have a few math questions on my profile consider looking at them i have to get done in 30 mins!

What is the probably of getting heads when poing a coin and getting a number greater than or equal to 5 when rolling a single diea) 1/6b) 1/3c) 1/4d) 1/12