Easy but Worth Trying

Prove that for all real a,b and c satisfying:
a^3+b^3=c^3

the following inequality holds:
a^2+b^2-c^2> 6(c-a)(c-b)

4 Answers

1
Dipanjan Das ·

Ne one trying?????
Come on, this is not so difficult...

1
Euclid ·

getting no idea!!!!! :(.....

1
Dipanjan Das ·

try this:
ac=x
bc=y

then
given condition : x3+y3=1

we have to prove: x2+y2-1> 6(1-x)(1-y)

assume x>y

for negative y, x>1 (Hope you come to the same conclusion)

so, 6(1-x)(1-y)<0
but LHS>0

so the inequality is established in this case....

now the case left for us to consider is : 0≤x≤1, 0≤y≤1.

I will leave that for u to try using my hint.

1
Dipanjan Das ·

ne one trying??

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