x^x = x, Find x? Only 1% solved This Tricky Olympiad Question | Math Doctor
Math Doctor
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x^x = x, Find x? Only 1% solved This Tricky Olympiad Question | Math Doctor
45 просмотров · 5 дней назад
Math Doctor
54 подписчика
45 просмотров · 5 дней назад
Can you solve this tricky Olympiad question?
Question: If x^x = x, Find x?
In this video Math Doctor solves the famous equation x^x = x step by step. Most students say only x=1, but there is a second hidden answer! We use the law a^0=1 and x^(x-1)=1.
Solution:
x^x = x ; x^x / x = 1 ; x^(x-1) = x^0 , x-1=0 , x=1
AND also check x=-1: (-1)^(-1) = 1/(-1) = -1 ; x=-1 also works!
Final Answer: x = 1, -1
What you will learn:
Laws of Exponents: a^0=1, a^m/a^n = a^(m-n)
How to solve x^x = k type equations
Why we must check negative case
Chapter / Topic:
Class 7: Exponents and Powers
Class 8: Exponents and Powers - Laws of Exponents
Class 9 & 10: Number System, Polynomials - Exponential Equations
Class 11 & 12: Relations and Functions, Exponential Functions
Boards:
CBSE, ICSE, IGCSE, IB, Cambridge, State Boards, NIOS
Exams Where This Type Comes:
Math Olympiad | IMO | RMO | INMO | PRMO | IOQM | NIMO | Math Kangaroo | UKMT | AMC | NTSE | SAT | ACT | JEE Mains | BITSAT | CAT | SSC CGL | UPSC CSAT | CUET | IPMAT
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