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Math Help - Square Root Problem

  1. #1
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    Square Root Problem

    How do I solve Z=the square root of L^2 + R^2 for R.
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  2. #2
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    I don't really know what you mean, but I'm guessing you want to make R the subject?

    Hence, step by step,

    => Z = (L^2 + R^2)^(1/2)
    => Z^2 = L^2 + R^2
    => R^2 = Z^2 - L^2
    => R = (Z^2 - L^2)^(1/2) <======
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  3. #3
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    Wouldn't it be:

    => R = +/- (Z^2 - L^2)^(1/2) <======

    the +/- because you're solving for all values of R
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  4. #4
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    Quote Originally Posted by Noxide View Post
    Wouldn't it be:

    => R = +/- (Z^2 - L^2)^(1/2) <======

    the +/- because you're solving for all values of R
    True, he didn't define the unknowns as positive values; this equation is very similar to the one I always use to solve physics questions; hence, I always disregard the - sign. lol, but thx for the correction!! I won't forget a lesson learnt.
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  5. #5
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    actually that sparked a question...

    when you are playing with variables in physics and you end up in a situation where x^(n/n) n is even do you put an absolute value symbol around x, or do you just remember that it's the positive case?
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  6. #6
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    I don't play with variables in physics, and didn't end up in that situation you desribed. I use that formula to usually find the " change in velocity ", " " change in displacement ", and etc; in other words, I use that formula to solve simple problems most of the time, and it becomes a habit to simply take the positive value as the answer without considering the possible negative value, which is most of the time needless.
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