An ac generator emf has emf E$=$E$\_($m$)$sin$(\backslash$omega $\_($d$)$t$-(\backslash$pi $)/(4)),$ where E$\_($m$)=25\mathrm{.}0$V and $\backslash$omega $\_($d$)=340$ra$($d$)/($s$).$ The current produced in a connected circuit is i$($t$)=$Isin$(\backslash$omega $\_($d$)$t$-3(\backslash$pi $)/(4)),$ where I$=650$mA$.$

$($a$)$ At what time after t$=0$ does the generator emf first reach a maximum?

s

$($b$)$ At what time after t$=0$F$,$H$,$ or $\backslash$Omega