(1)
∵∠ABC=90°→BC⊥AB
又∵SA⊥平面ABC→SA⊥BC
∴BC⊥平面SAB
∴BC⊥AE
又∵AE⊥SB
∴AE⊥面SBC
(2)
∵AE⊥面SBC
∴AE⊥SC
又∵AF⊥SC
∴SC⊥平面AEF
∴SC⊥EF