its simply.......for all real values of y except ZERO...........
PLS RATE IF CORRECT
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Aatish Pandit...IITD (civil)
AIR - 1445 ( IITJEE 2009 )
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One shud always either find a way, or make one !
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Best of luck to all my mates....
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Hey, see it is simple. it exists for y=R-{0} and for x=R-(-2,2). SIMPLY,by A.M.>=G.M. |(y^1/5 +y^-1/5)| /2 >= (y^1/5 * y^-1/5) |(y^1/5 +y^-1/5)|/2 >= 1 |(y^1/5 +y^-1/5)|>=2 i.e.|x|>=2 i.e. x=R-(-2,2) i have put modulus sign on (y^1/5+y^-1/5) because A.M--G.M. theorem can be applied on positive nos. only. also ,obyviously y can't be zero .