Find equation of the line through the point (0, 2) making an angle 2π3 with the positive x - axis. Also, find the equation of line parallel to it and crossing the y - axis at a distance of 2 units below the origin.
Here m=tan 2π3=tan120∘
=tan (90∘+30∘)=−cot 30∘=−√3
Equation of the line passing through point (0, 2) having slope −√3 is
y−2=−√3(x−0) ⇒ √3x+y+2=0
Now the line paralled to this line having slope −√3.
Here c = -2.
Putting these values in y = mx + c, we have
y=−√3x−2 ⇒ −√3x−y+2=0