Question

The differential equation of all circles in the first quadrant which touch the coordinate axes is of order -

• A. 1
• B. 2
• C. 3
• D. None of these

Answer 1

Answer: (A)

1

Centre of circle $=a,a$

Radius of circle $=a$

$\therefore$ Equation of circle -

$\Rightarrow {(x-a)}^2+{(y-a)}^2=a^2$

No. of arbitrary constants $=1$ ( i.e, a )

$\therefore$ Order of differential equations $=1$

Hence, the answer is $1.$