Can someone please help me understand ?
Mathematics

Tutor: None Selected  Time limit: 1 Day 
One model for the number of students enrolled in U.S. public high schools as a function of time since 1986 is the formula below.
(a) Use functional notation to express the number of students enrolled in U.S. public high schools in the year 1988.
Calculate that value. (Round your answer to one decimal place.)
Calculate N(6).
Thank you for the opportunity to help you with your question!
Here the given function is :
N = 0.05t^{2} − 0.42t + 12.33
Here N is the enrollment in millions of students, t is the time in years since 1986, and the model is relevant from 1986 to 1996.(a) Use functional notation to express the number of students enrolled in U.S. public high schools in the year 1988.
here the input to the function is t , which is years since 1986 , so t in 1988 would be = 1988 1986 = 2
so, the Functional Notion is N(2) = 0.05(2)^{2} − 0.42(2) + 12.33
calculating the value , N(2) = 0.05*4  0.84 +12.33 = 0.2 0.84 + 12.33 = 11.69 million
rounding to nearest decimal place, we get 11.7 million.
Calculate N(6) = 0.05(6)^{2} − 0.42(6) + 12.33 = 0.05*36  0.42*6 + 12.33 = 11.61 million
Secure Information
Content will be erased after question is completed.