Difference between revisions of "2021 JMPSC Sprint Problems/Problem 12"

(Created page with "==Problem== The solution to the equation <math>x \sqrt{x \sqrt{x}}=2^{63}</math> can be written as <math>2^m</math>, where <math>m</math> is a real number. What is <math>m</ma...")
 
(Solution)
Line 3: Line 3:
  
 
==Solution==
 
==Solution==
asdf
+
Let <math>y=\sqrt[4]{x}.</math> Then, we have that the expression on the left hand side is equivalent to <math>y^4\cdot y^2\cdot y=y^7.</math> Thus, we have that <math>y^7=2^{63}.</math> Taking the 7th root of both sides gives <math>y=2^9,</math> thus we have <math>\sqrt[4]{x}=2^9,</math> which makes <math>x=2^{36}.</math> Answer is <math>\boxed{36}.</math>
 +
 
 +
~Lamboreghini

Revision as of 23:05, 10 July 2021

Problem

The solution to the equation $x \sqrt{x \sqrt{x}}=2^{63}$ can be written as $2^m$, where $m$ is a real number. What is $m$?

Solution

Let $y=\sqrt[4]{x}.$ Then, we have that the expression on the left hand side is equivalent to $y^4\cdot y^2\cdot y=y^7.$ Thus, we have that $y^7=2^{63}.$ Taking the 7th root of both sides gives $y=2^9,$ thus we have $\sqrt[4]{x}=2^9,$ which makes $x=2^{36}.$ Answer is $\boxed{36}.$

~Lamboreghini