分析:
在三角形ABC中,A对边a,B对边b,C对边c,AB边上高为c,求
S=b/a+a/b+c^2/(ab)最大值.
S=b/a+a/b+c^2/(ab)
=(a^2+b^2+c^2)/(ab)
[余弦定理a^2+b^2-2ab cosc=c^2]
=(2c^2+2abcosc)/(ab)
[面积相等 1/2c^2=1/2ab sinc]
=(2absinc+2abcosc)/(ab)
=2(sinc+cosc)
=2√2 sin(c+45)
Smax=2√2
分析:
在三角形ABC中,A对边a,B对边b,C对边c,AB边上高为c,求
S=b/a+a/b+c^2/(ab)最大值.
S=b/a+a/b+c^2/(ab)
=(a^2+b^2+c^2)/(ab)
[余弦定理a^2+b^2-2ab cosc=c^2]
=(2c^2+2abcosc)/(ab)
[面积相等 1/2c^2=1/2ab sinc]
=(2absinc+2abcosc)/(ab)
=2(sinc+cosc)
=2√2 sin(c+45)
Smax=2√2