设y=a(x-1)²+16=ax ²-2ax+a+16x1+x2=2,x1x2=(a+16)/ax1 ²+x2 ²=(x1+x2) ²-2x1x2=4- 2(a+16)/a|x1-x2|=8x1 ²-2x1x2+x2 ²=644- 2(a+16)/a-2(a+16)/a=64-4(a+16)/a=60-4a-64=60aa=-...