Flag Algebra> prove this .. if a, b , c, are in h.p....
question mark

1/b-c + 1/b-a = 1/a + 1/c

shubham mishra , 13 Years ago
Grade 11
anser 3 Answers
Latika Leekha
I am not able to interpret your query. Please write down the problem clearly so that I can provide you the meaningful answer.
Thanks & Regards
Latika Leekha
askIITians faculty
Last Activity: 11 Years ago
SHAIK AASIF AHAMED
Hello student,
a, b, c are in HP, so 1/a, 1/b, 1/c are in AP,
->2/b - 1/a = 1/c
->(2a - b) / ab = 1/c
->c = ab/(2a - b)
=1/(b-a) + 1/(b-c)
= 1/(b-a) + 1/(b - ab/(2a - b) )
= 1/(b-a) + (2a - b)/( b(2a - b) - ab)
= 1/(b-a) + (2a - b)/ { b(2a - b - a) }
= 1/(b-a) + (2a - b) / {b ( a - b) }
= 1/(b-a) - (2a - b) / {b(b-a) }
= (b - (2a - b) )/ ( b(b-a) )
=(2b - 2a)/(b(b-a))
= 2(b-a)/(b(b-a)) = 2/b=1/a+1/c
Hence (1/b-c)+(1/b-a)=1/a+1/c
Thanks and Regards
Shaik Aasif
askIITians faculty
Last Activity: 11 Years ago
PARTH
Hello student,
a, b, c are in HP, so 1/a, 1/b, 1/c are in AP,
->2/b - 1/a = 1/c
->(2a - b) / ab = 1/c
->c = ab/(2a - b)
=1/(b-a) + 1/(b-c)
= 1/(b-a) + 1/(b - ab/(2a - b) )
= 1/(b-a) + (2a - b)/( b(2a - b) - ab)
= 1/(b-a) + (2a - b)/ { b(2a - b - a) }
= 1/(b-a) + (2a - b) / {b ( a - b) }
= 1/(b-a) - (2a - b) / {b(b-a) }
= (b - (2a - b) )/ ( b(b-a) )
=(2b - 2a)/(b(b-a))
= 2(b-a)/(b(b-a)) = 2/b=1/a+1/c
Hence (1/b-c)+(1/b-a)=1/a+1/c
Last Activity: 5 Years ago
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments