设直线ax+by+c的倾角为a,sina+cosa=0,则a,b满足?a-b=0
问题描述:
设直线ax+by+c的倾角为a,sina+cosa=0,则a,b满足?a-b=0
答
sina+cosa=0,
tana+1=0
tana=-1=k
ax+by+c=0
by=-ax-c
y=-ax/b-c/b
斜率k=-a/b=-1
a=b
a-b=0