Question

求函数y=3x^2+3x+4/x^2+x+1的最大值

Answer 1

y=(3x²+3x+3+1)/(x²+x+1)

=3(x²+x+1)/(x²+x+1)+1/(x²+x+1)

=3+1/(x²+x+1)

x²+x+1

=(x+1/2)²+3/4>=3/4

所以0