Question

1、y=（x+1）分之（x²+7x+10）的值域

Answer 1

1y=（x²+7x+10)/(x+1)=[(x+1-1)²+7(x+1-1)+10]/(x+1)=[(x+1)²-2(x+1)+1+7(x+1)-7+10]/(x+1)=[(x+1)²+5(x+1)+4]/(x+1)=(x+1)+4/(x+1)+5当x>-1时,x+1>0（x+1)+4/(x+1)≥2√[(x+1)*4/(x+1)]=4【当...