We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
0
128
4
avatar

What number must we add to $3-5i$ to get $2+7i$? Here $i$ denotes the imaginary unit $\sqrt{-1}$.

 May 15, 2019
 #1
avatar+28132 
+4

Let the unknown (complex) number be a + bi

 

Then  3 - 5i + a + bi = 2 + 7i

 

Subtract 3 - 5i from both sides:   a + bi = 2 + 7i - 3 + 5i or a + bi = -1 + 12i  

 

Equating real and imaginery parts we have:  a = -1,  b = 12. 

 May 15, 2019
 #2
avatar
0

So what number do you have to add?

 May 15, 2019
 #4
avatar+28132 
+1

The number you add is the complex number a + bi, which here is -1 + 12i.

Alan  May 15, 2019
 #3
avatar
0

Oops sorry I got it

 May 15, 2019

40 Online Users

avatar
avatar
avatar
avatar
avatar