Question

if x/y +y/x = -1 where x,y ≠ 0 then find the value of x³- y³.do it fast

Answer 1

the answer is 0.

here's the solution:

x/y + y/x =-1

(x2 +y2)/xy = -1

x2 +y2 = -xy    ----------------------(1)

now,

x3-y3 = (x-y)(x2 +y2 +xy)

x3-y3 = (x-y)(-xy + xy)

x3-y3 = (x-y)(0)

x3-y3 = 0.

     

Answer 2

Answe is = 0

Solution:

∵x/y + y/x = -1

∴ x²+y²/x×y = -1

x²+y² = -xy .......... (1)

∴ x³-y³ = (x-y)(x²+y²+xy)

Now using (1) we get,

            = (x-y)(xy-xy)

            = 0