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#explanatory answers needed
if a=x-y,
b=y-z,
c=z-x
then (x-y)³+(y-z)³+(z-x)³/3 (x-y)(y-z)(z-x)=?
#ntse-preparation
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These are the tricky questions,which makes you to think as harder ones and you will feel it time taking. But these are easy. A brilliant student takes 20-30 seconds.
Now, Going back to the question.
a=x-y,
b=y-z,
c=z-x
Here, a+b+c
=>x-y+y-z+z-x
=> 0.
We know that if a+b+c =0 then a³+b³+c³=3abc
[ a+b+c =0
=> a+b =-c
cubing on both sides,
(a+b) ^3 =-c^3
a³+b³+3ab(a+b)=-c³
wkt a+b=-c
a³+b³+3ab(-c)=-c³
a³+b³-3abc=-c³
a³+b³+c³=3abc ]
This is just for a reference, steps inside [ ] aren't required to be learnt.
Now back to question.
So here a+b+c =0
a³+b³+c³=3abc
replacing a,b,c by their values.
(x-y)³+(y-z)³+(z-x)³= 3 (x-y)(y-z)(z-x)
transposing the terms
we get (x-y)³+(y-z)³+(z-x)³/3 (x-y)(y-z)(z-x)=1
Now, Going back to the question.
a=x-y,
b=y-z,
c=z-x
Here, a+b+c
=>x-y+y-z+z-x
=> 0.
We know that if a+b+c =0 then a³+b³+c³=3abc
[ a+b+c =0
=> a+b =-c
cubing on both sides,
(a+b) ^3 =-c^3
a³+b³+3ab(a+b)=-c³
wkt a+b=-c
a³+b³+3ab(-c)=-c³
a³+b³-3abc=-c³
a³+b³+c³=3abc ]
This is just for a reference, steps inside [ ] aren't required to be learnt.
Now back to question.
So here a+b+c =0
a³+b³+c³=3abc
replacing a,b,c by their values.
(x-y)³+(y-z)³+(z-x)³= 3 (x-y)(y-z)(z-x)
transposing the terms
we get (x-y)³+(y-z)³+(z-x)³/3 (x-y)(y-z)(z-x)=1
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