How do you change y=x^2-10x-6 into vertex form

Fiona and her friends are playing a game by guessing where a coin will land when it is randomly dropped inside the square shown below. fiona guesses that the coin is likely to land in the blue area. which explains whether or not fiona is correct and why?

What is the frequency of the sinusoidal graph?

With alll of except for the 2 that i did already