Question

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

Answer 1

`2sqrt5,8" and "sqrt58`

Explanation:

`"given a complex number "x+yi`

`"then the absolute value is"`

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

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

`rArr|4+2i|=sqrt(4^2+2^2)=sqrt20=2sqrt5`

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

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

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

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