the function f(x) = 1 if x is rational(adsbygoogle = window.adsbygoogle || []).push({});

f(x) = 0 if x is irrational is not continuous for all real numbers, c

the function f(x) = x if x is rational

f(x) = 0 if x is irrationa is continuous at x=0 and not continuous for all other real numbers c

the function f(x) = 1/q if x is rational and x = p/q in lowest terms

f(x) = 0 if x is irrational

is continuous at c if c is irrational and not continuous at c if c is rational

I'm terrible at proofs, please help!

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Function proofs

**Physics Forums | Science Articles, Homework Help, Discussion**