Simple Problem STUMPS PhotoMath! Can You Figure It Out?

MindYourDecisions
3 Jan 201905:00

TLDRIn this video, Presh Talwalkar tackles an algebra problem that challenges solvers like PhotoMath and Mathway. The problem involves finding all real numbers x for which (x^2 - 7x + 11)^(x^2 - 13x + 42) equals 1. Talwalkar explains that while most solvers find four solutions, there are actually six. He demonstrates how to solve the problem by considering cases where the base or exponent equals one or the base is negative one and the exponent is even, leading to the solutions x = 2, 3, 4, 5, 6, and 7.

Takeaways

  • 🧠 The problem involves solving for x in the equation (x^2 - 7x + 11)^(x^2 - 13x + 42) = 1.
  • 📱 Popular math-solving apps like Photomath, Mathway, and Symbolab struggle to find all solutions, missing some.
  • 🔍 Wolfram Alpha is noted for successfully identifying all six solutions to the problem.
  • 🤔 The presenter suggests solving the problem by considering different cases where the expression can equal one.
  • 📝 The first case involves setting the base x^2 - 7x + 11 equal to 1, leading to solutions x = 2 and x = 5.
  • 🎯 The second case considers the exponent x^2 - 13x + 42 equal to 0, yielding solutions x = 6 and x = 7.
  • ⚠️ It's important to verify that the base is not zero to avoid an indeterminate form.
  • 🔄 The third case examines when the base is -1, requiring the exponent to be even, resulting in solutions x = 3 and x = 4.
  • 📉 The presenter uses graphing tools like Desmos to illustrate the solutions, although they initially suggest fewer solutions than actually exist.
  • 😄 A humorous note is made about the product of all solutions, prompting viewers to read a specific sentence aloud.
  • 🌟 The video concludes with a call to action for viewers to subscribe and support the channel for more free math content.

Q & A

  • What is the main challenge presented in the video?

    -The main challenge is to solve for all real numbers x for which the equation \((x^2 - 7x + 11)^{(x^2 - 13x + 42)} = 1\) holds true.

  • Why is this algebra problem considered difficult?

    -This problem is considered difficult because it stumps many computer solvers, including PhotoMath, which cannot provide step-by-step solutions and incorrectly suggests there are only four solutions when there are actually six.

  • What is the average time given to high school students in Massachusetts to solve similar problems?

    -High school students in Massachusetts are given an average of 30 minutes to solve each question.

  • How many solutions does Wolfram Alpha find for the given problem?

    -Wolfram Alpha is able to find all six solutions to the problem.

  • What are the different cases that can result in the equation equaling one?

    -The different cases include: 1) The base equation equals one, 2) The exponent equals zero with a non-zero base, and 3) The base equals negative one and the exponent is an even number.

  • What are the two solutions obtained from setting the base equation equal to one?

    -The solutions obtained by setting \(x^2 - 7x + 11 = 1\) are \(x = 2\) and \(x = 5\).

  • What are the two solutions obtained from setting the exponent equal to zero?

    -The solutions obtained by setting \(x^2 - 13x + 42 = 0\) are \(x = 6\) and \(x = 7\).

  • Why is it necessary to check that the base is not equal to zero?

    -It is necessary to check that the base is not equal to zero because \(0^0\) is an indeterminate form, which would not satisfy the original equation.

  • What are the two additional solutions found by setting the base equal to negative one?

    -The solutions obtained by setting \(x^2 - 7x + 11 = -1\) and ensuring the exponent is even are \(x = 3\) and \(x = 4\).

  • What is the total number of solutions to the problem presented in the video?

    -There are six solutions to the problem: \(x = 2, 3, 4, 5, 6,\) and \(7\).

  • What joke does the presenter leave the viewers with regarding the solutions to the problem?

    -The joke is about multiplying all of the solutions together, which is a playful nod to the complexity of the problem.

Outlines

00:00

🧮 Algebra Problem Introduction

Presh Talwalkar introduces an algebra problem to solve for all real numbers x that satisfy the equation \(x^2 - 7x + 11\) raised to the power of \(x^2 - 13x + 42\) equals 1. This problem was given to high school students in Massachusetts with an average of 30 minutes per question. The video challenges viewers to solve it and provides a solution later in the video. The problem's complexity is highlighted by the fact that many computer solvers, including popular apps like Photomath, Mathway, and Symbolab, fail to find all six solutions, with some only identifying four. Only Wolfram Alpha successfully finds all six solutions.

Mindmap

Keywords

💡Algebra

Algebra is a branch of mathematics that uses symbols and rules to solve for unknowns within an equation. In the context of the video, algebra is central to solving the problem presented. The video discusses solving an algebraic equation where \(x^2 - 7x + 11\) raised to the power of \(x^2 - 13x + 42\) equals 1. This involves factoring and understanding exponent rules, showcasing the fundamental role of algebra in mathematical problem-solving.

💡PhotoMath

PhotoMath is an app designed to solve mathematical problems by taking a photo of them. The video mentions that PhotoMath, despite its popularity, fails to provide a complete solution to the algebra problem, suggesting that not all mathematical problems can be easily solved by technology. This highlights the importance of human understanding and manual computation in mathematics.

💡Exponent Rules

Exponent rules are mathematical principles that govern operations involving exponents. In the video, exponent rules are crucial for solving the equation, as they help in determining when an expression raised to a power equals 1. The video explains that \(1^n = 1\) for any number, and \(a^0 = 1\) for any non-zero number 'a', which are key insights used to find the solutions.

💡Factoring

Factoring is the process of breaking down a polynomial into a product of its factors. The video script uses factoring to simplify the equation \(x^2 - 7x + 11 = 0\) and \(x^2 - 13x + 42 = 0\) to find the roots, which are essential in solving the algebra problem. Factoring is a fundamental technique in algebra that helps in understanding the structure of polynomials.

💡Indeterminate Form

An indeterminate form arises in mathematics when an expression does not have a unique value due to division by zero or other undefined operations. In the context of the video, the script mentions checking that the base of the exponent is not zero to avoid the indeterminate form \(0^0\). This is a critical step in ensuring the validity of the mathematical solutions.

💡Wolfram Alpha

Wolfram Alpha is a computational knowledge engine that can solve various mathematical problems. The video credits Wolfram Alpha for finding all six solutions to the problem, contrasting it with other solvers that missed some solutions. This highlights the tool's comprehensiveness and reliability in mathematical computations.

💡Desmos

Desmos is an online graphing calculator that allows users to visualize mathematical functions and equations. The video mentions that a graph on Desmos would suggest there are four solutions to the problem, which is incorrect. This example illustrates that while graphical tools can be helpful, they should be used in conjunction with other methods for verification.

💡Mind Your Decisions

Mind Your Decisions is the name of the channel presented by Presh Talwalkar, where this video is from. The channel focuses on mathematical and logical problem-solving, aiming to inspire and build confidence in viewers. The video script is part of a series that encourages viewers to engage with mathematical challenges and learn from them.

💡Presh Talwalkar

Presh Talwalkar is the host of the Mind Your Decisions channel and a mathematics educator. In the video, he presents and solves the algebra problem, demonstrating his expertise in mathematics. His approach to explaining complex mathematical concepts in an accessible way is a key feature of the video.

💡Mathematical Puzzle

A mathematical puzzle is a problem that requires logical thinking and mathematical skills to solve. The video presents a complex algebraic equation as a puzzle, challenging viewers to find all the solutions. This type of problem is designed to engage the audience's mathematical curiosity and problem-solving abilities.

Highlights

Solve for all real numbers x in the equation x^2 - 7x + 11 * (x^2 - 13x + 42)^x = 1.

The problem was given to high school students in Massachusetts with an average of 30 minutes per question.

Many computer solvers, including Photomath, do not provide correct solutions for this problem.

Photomath, with over a hundred million downloads, cannot solve this problem and suggests there are four solutions.

Mathway and Symbolab also miss two of the six solutions.

Desmos graph suggests four solutions, but there are actually six.

Wolfram Alpha is able to find all six solutions.

To solve, set the base equation x^2 - 7x + 11 equal to 1 and factor for solutions.

The solutions from the base equation are x = 2 and x = 5.

Set the exponent equal to zero for another case, leading to x^2 - 13x + 42 = 0.

Solutions from the exponent equation are x = 6 and x = 7.

Ensure the base is not zero to avoid an indeterminate form.

Set the base equal to negative one and check if the exponent is even for the third case.

Solutions from the base equal to negative one are x = 3 and x = 4.

The six solutions to the problem are x = 2, 3, 4, 5, 6, and 7.

Multiplying all the solutions together leads to a humorous outcome.

The video is part of a series on YouTube that has over 100 million views and aims to inspire confidence in math.

The presenter encourages subscriptions and engagement with the content.