Friday, February 17, 2017

algebra precalculus - Anything to zero power equals one?




I am in Adv. Algebra 2 and I have a question. Firstly, would like to say I haven't taken algebra in a year due to geometry (stupid order they do but oh well) and I have a question understanding this: (x+5)0. That would be x0+50 which then, wouldn't that be 1+1 since anything that has a power of 0=1? Maybe I misunderstood but that's what I got.


Answer



First, exponents do not distribute over addition. To start with the simplest example, (a+b)2=(a+b)(a+b). Applying the distributive rule, we see that this is the same as a(a+b)+b(a+b)=a2+ab+ab+b2, which is different from a2+b2. This can be seen geometrically, too: A square built on a side of length a+b has greater area than the square with side length a, combined with the square with side length b.



You can also see your result if you consider order of operations, and substitute an actual number for x. Let's consider x=3. Then we have:



(x+5)0=(3+5)0=80=1,



because Parentheses come before Exponents in PEMDAS.



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