已知,抛物线y=ax2+bx+c(a≠0)经过原点,顶点为A(h,k)(h≠0)
(1)当h=1,k=2时,求抛物线的解析式;
(2)若抛物线y=tx2(t≠0)也经过点A(h,k),求a与t之间的关系式.