要使点A(2,cosθ),B(sinθ,-(2/3)),C(-4,-4)共线,则θ的值为____.
kπ/2(k∈Z)。ABC三点共线,则kAB=kBC,从而得到(-2/3-cos2θ)/(sin2θ-2)=(-4-(-2/3))/(-4-sinsin2θ),可得到sinθ=0,所以θ=kπ/2(k∈z).
要使点A(2,cosθ),B(sinθ,-(2/3)),C(-4,-4)共线,则θ的值为____.
kπ/2(k∈Z)。ABC三点共线,则kAB=kBC,从而得到(-2/3-cos2θ)/(sin2θ-2)=(-4-(-2/3))/(-4-sinsin2θ),可得到sinθ=0,所以θ=kπ/2(k∈z).