Mathematics Desperate Help?

Hello. How Would I Do This and What would the answers to the questions be?A mathematically minded student took temperature readings on a particular day between 5.00 am and 11.00 pm. He discovered that the temperature Do at a time t hours after 5.00 am was given by= -1/4 (t-8) 2 + 20 0 ≤ t ≤ 18a)Determine the t-intercept, D-intercept and the c-ordinates of the turning pointb)Make a neat sketch of the graphc)What was the temperature at 9.00 amd)At what time was the temperature 11oe)What was the maximum temperature and when did it occurPlease Help