op$.$ amp is ideal

a$)$ find the relationstup between volt$)$ and vi$($t$)$

b$)$ if ve $(0)=2$V and vi$($t$)=$SV t$>=$o $,$ find volt$)$

c$)$ find vcit$)$ for part $($b$)$

d$)$ roughly sketch volt$)$ and vc$($t$)$