Question

If lz2/mz1 is a imaginary number

Answer 1

Given,

let lz2/mz1 = iy

z2/z1 = iym/l

⇒|lambda z1+µz2/lamda z1-µz2|

   dividing numerator and denominator by z1 we get

⇒|lambda(1)+µ(z2/z1) / lambda(1)-µ(z2/z1)|

    we know that z2/z1 = imy/l 

⇒|lambda+µ(imy/l) / lambda-µ(imy/l)|

    we know that |x+iy| = root of (x2+y2)

⇒square root(lambda² + µ²y²/l² )/square root( lambda² + µ²y²/l²)

⇒1

hope this helps :)