8. 函数y=loga(x+1)(a>0y=\log _{a}(x+1)(a>0y=loga(x+1)(a>0,且a≠1)a\ne 1)a=1)与函数y=x2−2ax+1y=x^{2}-2ax+1y=x2−2ax+1在同一直角坐标系中的图象大致是((( )))