MHB Can You Solve This Week's Math Challenge Equation?

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    2016
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The math challenge presented is to solve the equation x^3 = 4 + ⌊x⌋. Participants are encouraged to refer to the Problem of the Week guidelines for submission procedures. IanCg successfully provided the correct solution to the equation. The discussion highlights the importance of engaging with mathematical problems collaboratively. This week's challenge fosters problem-solving skills within the community.
anemone
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Here is this week's POTW:
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Solve the equation $$x^3=4+\left\lfloor{x}\right\rfloor$$.

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Remember to read the http://www.mathhelpboards.com/showthread.php?772-Problem-of-the-Week-%28POTW%29-Procedure-and-Guidelines to find out how to http://www.mathhelpboards.com/forms.php?do=form&fid=2!
 
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Congratulations to IanCg for his correct solution, which you can find below::)

For $x < 0,\, x^3-4 < x-1 \leqslant\left\lfloor{x}\right\rfloor$ so there are no solutions in this range
For$ x >2,\, x^3 - 4 > x \geqslant\left\lfloor{x}\right\rfloor$ so no solutions in this range
for $0\le x < 1,\, x^3-4$ is negative and $\left\lfloor{x}\right\rfloor = 0$ so no solutions

View attachment 6303

The only range for a solution is $1\le x<2$ in this case $\left\lfloor{x}\right\rfloor = 1$
So the equation becomes $x^3 - 4 = 1 $
So the solution is $x = \left\lfloor{\sqrt[3]{5}}\right\rfloor$
 

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