Question 1065420
I'll do one you do the rest,
Also, it's not the over sign, it's the division symbol. 
You should also use parentheses to separate numerator and denominator,
f(x)=x/(x^2+1) is clear while 
f(x)=x/x^2+1 could mean {{{x/x^2+1}}} or {{{x/(x^2+1)}}}
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a){{{f(x)=x/(x^2+1)}}}
{{{f(1)=1/((1)^2+1)=1/(1+1)=1/2}}}
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How is b different from a?
Now do the rest the same way by substituting x.