How do you find absolute value of 4+2i, 8i, and -3 + 7i?

1 Answer
Apr 15, 2018

2sqrt5,8" and "sqrt5825,8 and 58

Explanation:

"given a complex number "x+yigiven a complex number x+yi

"then the absolute value is"then the absolute value is

•color(white)(x)|x+yi|=sqrt(x^2+y^2)x|x+yi|=x2+y2

4+2i" has "x=4" and "y=24+2i has x=4 and y=2

rArr|4+2i|=sqrt(4^2+2^2)=sqrt20=2sqrt5|4+2i|=42+22=20=25

8i" has "x=0" and "y=88i has x=0 and y=8

rArr|8i|=sqrt(0^2+8^2)=8|8i|=02+82=8

-3+7i" has "x=-3" and "y=73+7i has x=3 and y=7

rArr|-3+7i|=sqrt((-3)^2+7^2)=sqrt58|3+7i|=(3)2+72=58