what would be the square root of -0.64?

Answer 1

There are 2 solutions, ±0.8i

where i = √-1

Answer 2

There is, at least in the Real Number system, no square root of ANY negative number. That is because a - X a- =a+. It's tempting to write the square root of
-0.64 as -0.8,but as you probably already know,
(-.8)(-.8) = + .64

There is a way around this, and that is to introduce the concept of Imaginary Numbers. Without going too deeply into this, we introduce(sq.rt.-1) into our number system. This is called the Complex Number System.

(sq.rt.-0.64) can now be written as (sq.rt.-1)(sq.rt0.64). Sq.rt.-1 is given the symbol i,so your problem has the answer0.8i

Welcome to the world of Complex numbers, although I suspect the answer that the teacher wants is that you cannot take the sq.rt. of -0.64. Give him or her
0.8i as an answer and dazzle them!
Good luck

Answer 3

Hey there!

Rewrite sqrt(-0.64) as the product of sqrt(-1) and sqrt(0.64). Our main intention is to isolate the -1 from the problem, since we can not find the sqrt(-1). Our answer would probably be 0.8sqrt(-1). However, there is a particular number for sqrt(-1), which is i. So replace sqrt(-1), with i. The answer would be 0.8i. However, the square root did not specify whether it is a positive or a negative square root. The square root could be both. So the answer would be either 0.8i or -0.8i, which would simplify to ±0.8i.

So the answer is ±0.8i.

Hope it helps!

Answer 4

-0.8

8x8=64

Square Roots
1x1=1
2x2=4
3x3=9
4x4=16
5x5=25
6x6=36
7x7=49
8x8=64
9x9=81
10x10=100
11x11=132
12x12=144

Answer 5

the square root of +.64 is .8

when you take the square root of a negative number, i (imaginary) comes into play. i^2 = -1

so sqrt(-.64) = +- .8i

Answer 6

Answer = Plus or Minus 0.8i

Answer 7

√ -0.64
√ (.64)(-1)

= - .8i
and
= +.8i


PS... √(-1) = i

Answer 8

.8 i

Answer 9

√ [ (- 1) x ( 64) x 10^(-2) ]
(1/10) ± √ [ (i ²) (64) ]
(1/10) (± 8 i)
± (0.8 i)