(2) On the 27th day after the first batch of product A went on the market, the company's daily sales profit was the largest, with the highest profit of 10000 yuan.

Test analysis: (1) First, set f(t)=a(t-20) 2 +60 according to the meaning of the test, and get the value of A from f(0)=0, and get the relationship between the daily sales volume of the first batch of products A and the time to market T;

(2) Write the sales profit as g(t) 10,000 yuan, and discuss them by classification: when 30≤t≤40 and 0 ≤ t ≤ 30, study their monotonicity, t∈N, so compare g(26) and g(27), and after calculation, G (26) < G

Solution: (1) hypothesis, from which we can know that

Namely; .........................., 4 points.

(2) If the sales profit is 10000 yuan, then

? Eight points, eight points, eight points

When, monotonously decreasing;

At this time, it is easy to know whether the company is increasing or decreasing. However, through comparison and calculation, the company's daily sales profit is the largest on the 27th day after the first batch of product A is listed, and the maximum profit is 10000 yuan. .....................................................................................................

Comments: The function model to solve this problem is piecewise function. To find the maximum value of piecewise function, we first require the maximum value of each part of the function, then take the maximum value of each part as the maximum value of the whole function and the minimum value of each part as the minimum value of the whole function.