+0  
 
0
61
1
avatar

Ramanujan and Hardy played a game where they both picked a complex number. If the product of their numbers was 17 - 20i, and Hardy picked 7 - 2i, what number did Ramanujan pick?

 Dec 5, 2020
 #1
avatar+31533 
+1

"Ramanujan and Hardy played a game where they both picked a complex number. If the product of their numbers was 17 - 20i, and Hardy picked 7 - 2i, what number did Ramanujan pick?"

 

Let Ramanujan number be a + bi, then

 

(a + bi)*(7 - 2i) = 17 - 20i

 

7a - 2ai + 7bi + b = 17 - 20i

 

Equate real and imaginary parts:

 

7a + b = 17

-2a + 7b = -20

 

Solve these two equations for a and b.

 Dec 5, 2020

40 Online Users

avatar
avatar
avatar