if x+y+z=1,xy+yz+zx=-1 and xyz=-1 then find 1/x^-3+1/y^-3+1/z^-3
Answers
Answered by
3
x3+y3+z3=3-2=1 that is the answer
mysticd:
write steps
Identity:x3 +y3 +z3 -3xyz = (x+y+z)( x2 +y2 +z2 -xy-yz-zx)
Since x + y + z = 1, xy + yz + zx = -1and xyz= -1,
Putting values, we get:
So
Now
(x+y+z)2 = x2 +y2 +z2 +2xy +2yz +2zx
12 = x2 +y2 +z2 +2(-1)
x2 +y2 +z2 = 3
Put in eq (i)
x3 +y3 +z3 =3-2 = 1
Since x + y + z = 1, xy + yz + zx = -1and xyz= -1,
Putting values, we get:
So
Now
(x+y+z)2 = x2 +y2 +z2 +2xy +2yz +2zx
12 = x2 +y2 +z2 +2(-1)
x2 +y2 +z2 = 3
Put in eq (i)
x3 +y3 +z3 =3-2 = 1
Answered by
3
this is the solution
Attachments:
thnxxxxx bro
whats your name
neha
thnxxxx sis
welcome bro
can you give this question answers please. if x=9-4√5 then find x^3+1/x^3
solving
Similar questions