在△ABC中,AB=CB,∠ABC=90º,F为AB延长线上一点,点E在BC上,且AE=CF. ⑴求证:Rt△ABE≌Rt△CBF; ⑵若∠CAE=30º,求∠ACF度数.
(南宁)计算:.
(贺州)计算:.
(河池)先化简,再求值:,其中.
(河池)计算:.