直线l1:2x+y－7=0,l2:3x－y－4=0的夹角θ=_______________________.
问题描述：
直线l1:2x+y－7=0,l2:3x－y－4=0的夹角θ=_______________________.
答
k1=-2
k2=3
tanθ=|(k1-k2)/(1+k1k2)|=|(-5)/(1-6)|=1
直线l1:2x+y－7=0,l2:3x－y－4=0的夹角θ=____45°_________.