如图,E是⊙O内接四边形 ABCD两条对角线的交点,CD延长线与过 A点的⊙O的切线交于F点,若∠ABD=440,∠AED=1000, , 则∠AFC的度数为( )
A.B C. D.
A.(x+B (log2x)′= C.(3x)′=3xlog3e D.(x2cosx)′=-2xsinx
A.30°B 45° C.60° D.135°
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