What is the other equation? what is x and y

Could someone with number 1 and 2

Fred has a spinner that is split into four equal sections: red, blue, green, and yellow. fred spun the spinner 688 times. which of the following would be a good estimate of the number of times the spinner lands on the green section? a. 269 b. 603 c. 344 d. 189

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