Study the continuity of this function

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The function f(x) = [x^2]sin(πx) is being analyzed for continuity, where [x] denotes the integer part of x. While sin(πx) is continuous everywhere, the integer part function [x^2] introduces discontinuities at integer values of x^2. Therefore, the product f(x) is not continuous across all real numbers due to the discontinuities from [x^2]. The initial assumption that f(x) is trivially continuous is incorrect, as the integer part function disrupts continuity. The key takeaway is that f(x) is continuous except at points where x^2 is an integer.
Felafel
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Homework Statement



f(x) = [x^2]sinπx, x ∈ R, being [x] the integer part of x


Homework Equations





The Attempt at a Solution



I'd say it's trivially continuos on all R, because it's the product of two continuos functions: y: = [x^2] and g: = sinπx.
However, being part of my analysis class homework (always a bit tricky to solve), it seems a bit too easy to me. So, i thought there might be something strange I haven't noticed. Or is my reasoning just correct?
thanks in advance!
 
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Felafel said:

Homework Statement



f(x) = [x^2]sinπx, x ∈ R, being [x] the integer part of x


Homework Equations





The Attempt at a Solution



I'd say it's trivially continuos on all R, because it's the product of two continuos functions: y: = [x^2] and g: = sinπx.
However, being part of my analysis class homework (always a bit tricky to solve), it seems a bit too easy to me. So, i thought there might be something strange I haven't noticed. Or is my reasoning just correct?
thanks in advance!

x^2 is continuous. The integer part of x^2 is not continuous.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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