Chapter 13: Problem 63
Use a calculator to solve the given equations. $$2^{x}+3^{x}=50$$
Short Answer
Expert verified
\(x \approx 3.32\) is the solution.
Step by step solution
01
Understanding the Equation
First, we need to comprehend the equation we are dealing with: \(2^{x} + 3^{x} = 50\). This equation involves two exponential terms with the same variable, \(x\), as the exponent, to be solved using a calculator.
02
Initial Guess and Inspection
Using logical reasoning, we estimate a potential solution by considering smaller integer values for \(x\). We try \(x = 3\):\(2^{3} = 8\) and \(3^{3} = 27\).Thus, \(8 + 27 = 35\), which is less than 50.
03
Second Guess and Verification
Next, try \(x = 4\):\(2^{4} = 16\) and \(3^{4} = 81\).Thus, \(16 + 81 = 97\), which is more than 50, implying the value of \(x\) lies between 3 and 4.
04
Testing Fractional Values
Test a value in between, such as \(x = 3.5\):Calculate using a calculator:\(2^{3.5} \approx 11.31\) and \(3^{3.5} \approx 46.77\).So, \(11.31 + 46.77 \approx 58.08\), which is greater than 50.
05
Final Adjustment and Accurate Solution
Recognize the need for a smaller value, try \(x = 3.3\):Use a calculator again:\(2^{3.3} \approx 10.08\) and \(3^{3.3} \approx 39.42\).Thus, \(10.08 + 39.42 = 49.50\), which is slightly under 50.
06
Finding Exact Solution
Continue narrowing down until you reach the closest possible sum to 50. Using trial and error, finding approximately \(x = 3.32\) yields:\(2^{3.32} \approx 10.104\) and \(3^{3.32} \approx 39.899\).So \(10.104 + 39.899 = 50.003\), very close to 50. Therefore, \(x \approx 3.32\).
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Calculator Use in Mathematics
The use of a calculator in mathematics serves as a powerful tool for solving complex problems efficiently. Whether you are calculating basic arithmetic or more advanced functions like exponential equations, a calculator helps you process calculations that would be cumbersome by hand.
For exponential equations like \(2^x + 3^x = 50\), calculators can rapidly evaluate power terms, especially when accuracy is crucial. When using a calculator, inputting the exact expression into the calculator ensures that step-by-step approximations or trial-and-error attempts are consistent with variables' exponential growth. Calculators also help verify results quickly and precisely.
For exponential equations like \(2^x + 3^x = 50\), calculators can rapidly evaluate power terms, especially when accuracy is crucial. When using a calculator, inputting the exact expression into the calculator ensures that step-by-step approximations or trial-and-error attempts are consistent with variables' exponential growth. Calculators also help verify results quickly and precisely.
- Ensure the calculator is set to the appropriate mode (degree/radian when necessary).
- Use functions for exponential and roots effectively.
- Check each step with calculator outputs to confirm results.
Approximation Methods
Approximation methods are essential in solving equations where a precise analytical solution is not readily available. When dealing with an equation like \(2^x + 3^x = 50\), exact solutions may lie between integers, making exact calculations challenging.
One common approach is to make logical initial guesses—a critical part of approximating solutions. By trying different integer and non-integer values for \(x\) and evaluating the resulting expressions, you can hone in on a more precise answer.
One common approach is to make logical initial guesses—a critical part of approximating solutions. By trying different integer and non-integer values for \(x\) and evaluating the resulting expressions, you can hone in on a more precise answer.
- Start with easy-to-compute integer values to understand the equation's behavior.
- Use calculators to test fractional values for greater precision.
- Fine-tune further calculations to narrow down the solution.
Trial and Error Method
The trial and error method is a straightforward, intuitive strategy when working through equations with unknown values. This approach systematically tests values to narrow down possible solutions without needing sophisticated algebraic steps.
For exponential equations, such as \(2^x + 3^x = 50\), guesswork coupled with calculators can effectively approach an accurate solution. By initially testing a broad range of potential \(x\) values, you can quickly bracket the solution between two points—much like finding landmarks along a path to your destination.
For exponential equations, such as \(2^x + 3^x = 50\), guesswork coupled with calculators can effectively approach an accurate solution. By initially testing a broad range of potential \(x\) values, you can quickly bracket the solution between two points—much like finding landmarks along a path to your destination.
- Begin with broad, reasonable guesses and note the result.
- Systematically adjust the guesses based on previous outcomes to fine-tune results.
- Improve accuracy by working through smaller intervals.