Question

# The differential equation for all the straight lines which are at a unit distance from the origin is (B)(y+ (B) - 1301181626) 130118116261 V- (A)(y-4d=--() ©(y- --

Solution

Equation of the line: y = ax + b;
Distance from the line to origin: d = = 1 → b= Iva2 + 1
So y = ax + Va2 +1 – dy = a (ax i Va? + 1) ~ y' = a
and y = y'x + Vy!2 +1(y – xy')2 = y2 +1