An algebra problem by Anika Jahin

Algebra Level 3

Suppose z z is a complex number which value is ( x + i y ) (x+iy) where x = 2 , y = 3 x=2, y=3 , what's the value of ( z ⋅ z ′ ) (z \cdot z') ?


The answer is 13.

Anika Jahin by Anika Jahin , 25, Bangladesh

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

2 solutions

Tapas Mazumdar
Mar 23, 2017

z = 2 + 3 i z = 2+3i and z ⋅ z ′ = ∣ z ∣ 2 ⟹ ( 2 2 + 3 2 ) 2 = 13 z \cdot z' = {|z|}^2 \implies {\left( \sqrt{2^2+3^2} \right)}^2 = \boxed{13} .

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Tom Engelsman
Mar 12, 2017

z = 2 + 3 i z = 2 + 3i and z ′ = 2 − 3 i ⇒ z z ′ = ( 2 + 3 i ) ( 2 − 3 i ) = 4 − 9 i 2 = 13 . z' = 2 - 3i \Rightarrow zz' = (2+3i)(2-3i) = 4 - 9i^2 = \boxed{13}.

0 Helpful 0 Interesting 0 Brilliant 0 Confused

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...