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Question..

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Fitness:

--- Quote from: "reg" ---Er, excuse my poor expression perhaps, but any (-ve)^2 will be positive, which is what I meant.
--- End quote ---

Sorry, misread.

This is a clever question.

kido_1:
Absolute value function can be identified when you have a sqrt (something) squared.

E.g sqrt(9x+1)squared  is equal to abs(9x+1)

This is because a square root can only produce positive real values, just like an abs function.

reg:
I dno about specific technique, but if a function exists x < 0, and x is being squared, you are losing its sign, it will be positive regardless.

With your function you can see how sqrt(x ^ 2) can only ever be positive, it's  , as you say, equal to |x|.

x on its own is equal to both the -ve and +ve values.

hifer:
yup, got that now thx guys

Ninox:

--- Quote from: "reg" ---I dno about specific technique, but if a function exists x < 0, and x is being squared, you are losing its sign, it will be positive regardless.

With your function you can see how sqrt(x ^ 2) can only ever be positive, it's  , as you say, equal to |x|.

x on its own is equal to both the -ve and +ve values.
--- End quote ---


When any real number is squared it becomes positive. However, the square root of any positive number could be positive or negative. Going in the reverse again, "all real numbers" includes both positive and negative values. So (-3)^2 = (3)^2 = 9
And root(9) = +/-3

Hope that helps

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