Question

3. If 2( x2 +y2) = (x+y) find the value of x:y.​

Answer 1

Answer:

Given, 2

x

+2

y

=2

x+y

On differentiating w.r.t. x, we get

2

x

(log2)+2

y

(log2)

dx

dy

=2

x+y

(log2)(1+

dx

dy

)

⇒2

x

+2

y

dx

dy

=2

x+y

+2

x+y

(

dx

dy

)

⇒

dx

dy

(2

y

−2

x+y

)=2

x+y

−2

x

⇒

dx

dy

=

2

y

−2

x+y

2

x+y

−2

x

Therefore, (

dx

dy

)

x=y=1

=

2−2

2

2

2

−2

=

−2

2

=−1