题目

—Did you have a good time?—It couldn't be worse. We were held up on the expressway for three hours. On the way back, we found the car got a f tyre, and the spare was, too. 答案：【1】flat已知函数f（t）对任意实数x，y都有f（x+y）=f（x）+f（y）+3xy（x+y+2）+k（x+y）+3，k为常数，且f（1）=1，f（2）=17．（1）若t为正整数，求f（t）的解析式（已知公式：12+22+32+…+n2=16n(n+1)(2n+1)；（2）求满足f（t）=t的所有正整数t；（3）若t为正整数，且t≥4时，f（t）≥mt2+（4m+1）+3m恒成立，求实数m的最大值．