问题
填空题
Rt△ABC中,∠C=90°,若a=8,b=6,则sinB=______;若b=24,c=30,则cotA=______.
答案
(1)Rt△ABC中,∠C=90°,a=8,b=6,
则c=
=10,a2+b2
∴sinB=
=b c
,3 5
(2)b=24,c=30
则a=
=18,c2-b2
∴cotA=
=a b
.4 3
故答案为
,3 5
.4 3
Rt△ABC中,∠C=90°,若a=8,b=6,则sinB=______;若b=24,c=30,则cotA=______.
(1)Rt△ABC中,∠C=90°,a=8,b=6,
则c=
=10,a2+b2
∴sinB=
=b c
,3 5
(2)b=24,c=30
则a=
=18,c2-b2
∴cotA=
=a b
.4 3
故答案为
,3 5
.4 3