1.∵a^2+b^2=6abcosC,而由余弦定理
a^2+b^2=c^2+2abcosC
∴c^2=4abcosC (1)
又sin^2(C)=2sinAsinB, 即有c^2=2ab (2)
比较(1)(2)两式得
cosC=1/2
C=60°
2.f(x)=sin(ωx-π/6)-cosωx
=√3/2sinωx-3/...
1.∵a^2+b^2=6abcosC,而由余弦定理
a^2+b^2=c^2+2abcosC
∴c^2=4abcosC (1)
又sin^2(C)=2sinAsinB, 即有c^2=2ab (2)
比较(1)(2)两式得
cosC=1/2
C=60°
2.f(x)=sin(ωx-π/6)-cosωx
=√3/2sinωx-3/...