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Math Help - functions and domains

  1. #1
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    Unhappy functions and domains

    Let f(x)=square root (1+x) and g(x)=square root (1-x) Find f+g, f-g, fg, f/g and their domains.

    I know that to add these functions, I have to add sqrt (1+x) and sqrt (1-x) but I'm unclear how to add square roots and I'm not sure how to find the domains.
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  2. #2
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    Quote Originally Posted by sjenkins View Post
    Let f(x)=square root (1+x) and g(x)=square root (1-x) Find f+g, f-g, fg, f/g and their domains.

    I know that to add these functions, I have to add sqrt (1+x) and sqrt (1-x) but I'm unclear how to add square roots and I'm not sure how to find the domains.
    Domain of \sqrt{1+x} is x\geq -1.
    Domain of \sqrt{1-x} is x\leq 1.

    Thus, domain of f+g,f-g,fg is die intersection i.e. -1\leq x\leq 1

    While domain of f/g is -1\leq x\leq 1 minus 1 since denominator is zero.
    This gives us -1\leq x <1.
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