A) Let f: D -> R and define |f|: D->R by |f|(x) = |f(x)|. Suppose that f is continuous at c element of D. Prove that |f| is continuous at C
B) if |f| os cpmtomipis at c. does it follow that f is continuous at c? Justify your answer.
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For part A just see that: ||f(x)|-|f(c)||<|f(x)-f(c)|.
Review part B; canít read it.
sorry, that funky word is suppose to say continuous
Consider F(x)=-1 if x<0 and F(x)=1 if x>0.
Is |F| continuous at 0?
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