What is your answer: 1/a+1/b=1/a+b, Help me, a=?, b=?
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1/a + 1/b = 1/(a + b)
( a + b) /ab = 1/( a + b)
(a + b)^2 = ab
a^2 + b^2 +2ab = ab
a^2 + b^2 + ab =0 -----------(1)
we know ,
a^3 - b^3 =(a - b)(a^2 + b^2 + ab)
put equation (1)
a^3 - b^3 = (a - b)(0)= 0
a^3 = b^3
take cube root
a = b
now,
1/a + 1/b =2/a
but given,
1/a + 1/b =1(a+b)
because both are opposite nature.
so, This isn't possible .
( a + b) /ab = 1/( a + b)
(a + b)^2 = ab
a^2 + b^2 +2ab = ab
a^2 + b^2 + ab =0 -----------(1)
we know ,
a^3 - b^3 =(a - b)(a^2 + b^2 + ab)
put equation (1)
a^3 - b^3 = (a - b)(0)= 0
a^3 = b^3
take cube root
a = b
now,
1/a + 1/b =2/a
but given,
1/a + 1/b =1(a+b)
because both are opposite nature.
so, This isn't possible .
kvnmurty:
there is a mistake: if a = b.. then 1/a + 1/b = 2/a..... BUT 1/(a+b) = 1/2a..... they are not equal...
Answered by
1
1/a + 1/b = 1/(a+b)
(a+b) / ab = 1/(a+b)
(a+b)² = ab
a² + b² + 2 ab = ab
a² + b² = - a b
We know that always a² + b² >= 2 a b as (a-b)² >= 0
but - a b < 2 a b
Hence there is no solution to the given problem.
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Another way:
a² + b² = - ab
As LHS is always positive, a*b is negative. Let us assume that b is negative.
let b = - c , where c is positive. and a is positive.
So a² + c² = a c
a² + c² - 2 a c = - a c
(a - c)² = - a c
This is not possible. There is no solution to the given problem. There are no real a , b such that 1/a + 1/b = 1/(a+b).
(a+b) / ab = 1/(a+b)
(a+b)² = ab
a² + b² + 2 ab = ab
a² + b² = - a b
We know that always a² + b² >= 2 a b as (a-b)² >= 0
but - a b < 2 a b
Hence there is no solution to the given problem.
======
Another way:
a² + b² = - ab
As LHS is always positive, a*b is negative. Let us assume that b is negative.
let b = - c , where c is positive. and a is positive.
So a² + c² = a c
a² + c² - 2 a c = - a c
(a - c)² = - a c
This is not possible. There is no solution to the given problem. There are no real a , b such that 1/a + 1/b = 1/(a+b).
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