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Grade 11Algebra

This is a question based on complex number. It is taken from my rbse students advisor book of class 11th

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Profile image of Arvind sharma
6 Years agoGrade 11
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2 Answers

Profile image of Vikas TU
6 Years ago
Hiii 
Let Z1 = x1 +iy1
Z2 = x2 + iy2
So, Z2 conjugte = x2-iy2
arg (Z1Z2bar) = arg (x1x2 +x1y2 i +x2y1 i + y1y2)
=> Tan inverse {( x1y2 + x2y1)/(x1x2 + y1y2)
On RHS 
Tan inv (y1/x1) – Tan inv ( y2/x2)
Apply the formula Tan inv (A ) – Tan inv (B) = Tan inv (A-B )/ (1+AB) 
LHS = RHS 
Hence prooved 
Profile image of Saurabh Koranglekar
6 Years ago
Dear student

Arg( z1 z2) = arg (z1) + arg ( z2)

Also arg ( z') = - arg ( z)

Here replace z2 with z2'

Arg ( z1 z2') = arg ( z1) - arg( z2)

Regards