y=2x^2-2ax+2a+1 =2(x-a/2)^2-a^2/2+2a+1顶点是(a/2,-a^2/2+2a+1)y=x^2-(b-2)x+b =[x-(b-2)/2]^2-(b-2)^2/4+b顶点是((b-2)/2,-(b-2)^2/4+b)两抛物线顶点相同则a/2=(b-2)/2,-a^2/2+2a+1=-(b-2)^2/4+b解得a=2,b=4则抛物线方程分别为y=2(x-1)^2+7,y=(x-1)^2+7两个函数的增区间是[1,正无穷)