Question

Example 11. Find the differential equation for all straight lines, which are at a unit distance from the origin ​

Answer 1

Answer:

Correct option is

C

(y−xdxdy)2=1+(dxdy)2

Let the line be : y=mx+c

⇒1=m2+1∣c∣

⇒y=mx±m2+1

⇒dxdy=m

⇒y=xdxdy±(dxdy)2+1

⇒(y−xdxdy)2=1+(dxdy)2