Sponsor Area

Vector Algebra

Question
CBSEENMA12032927

Find the differential equation that will represent the family of curves given by (a, b: parameter):
x2 + y2 = a x3

Solution
The given differential equation is
                    straight x squared plus straight y squared space equals space ax cubed                             ...(1)
            2 straight x plus 2 straight y dy over dx space equals 3 ax squared                           ...(2)
Multiply (1) by 3 and (2) by x, we get,
                    3 straight x squared plus 3 straight y squared space equals space 3 ax cubed                     ...(3)
              2 straight x squared plus 2 xy dy over dx space equals space 3 ax cubed                    ...(4)
Subtracting (4) from (3), we get
                 straight x cubed plus 3 straight y squared minus 2 xy dy over dx equals 0
or             straight x squared plus 3 straight y squared equals 2 xy dy over dx
which is required differential equation.