1) To find a square root means to find the number that multiplied by itself gives you the given number. Since both a positive number multiplied by itself and a negative number multiplied by itself give you a positive number, we can say that every positive number has two square roots, one positive and one negative.
In order to find the square root of 0.0064, you need to think the number without the comma, in your case then 64. The square root of 64 is 8 (indeed 8x8=64).
You know need to decide how many decimals your root needs to have: since the given number had 4 decimals, you have to halve, therefore your root will have 2 decimal: 0.08
The square roots you are looking for are +0.08 and -0.08
2) To find the real-number root means to find the number that gives you real roots if square rooted. Since negative numbers give you imaginary numbers if square rooted, your answer has to be 1.1, the only positive number.
