Question

prove that 1/a+1/b =1/c

Answer 1

Heya User,

--> SInce ABCD is a square ... =_= we have the above and the following result 0_0 -->

--> AD || BC => AD || PQ

Now, Basic Proportionality Theorem says that, if AD || PQ :->
--> RE / RF = AD / PQ

=> RE / b = c / a
=> ( RF - EF ) / bc = 1/a
=> ( 1 / a ) = [ b - EF ] / bc

However, EF = AB = AD = c --> [ a square ]

=> ( 1 / a ) = ( b - c ) / bc
=> ( 1 / a ) = ( 1 / c ) - ( 1 / b )
=> ( 1 / a ) + ( 1 / b ) = ( 1 / c )  <-- We're done.. 0_0