Question

Some versions of our program for calculating the formula (1.2) are listed below. Determine which versions that will not work correctly and explain why in each case. $$ \begin{array}{llll} \mathrm{C}=21 ; & \mathrm{F}=9 / 5 * \mathrm{C}+32 ; & & \text { print } \mathrm{F} \\ \mathrm{C}=21.0 ; & \mathrm{F}=(9 / 5) * \mathrm{C}+32 ; & & \text { print } \mathrm{F} \\ \mathrm{C}=21.0 ; & \mathrm{F}=9 * \mathrm{C} / 5+32 ; & & \text { print } \mathrm{F} \\ \mathrm{C}=21.0 ; & \mathrm{F}=9 . *(\mathrm{C} / 5 \cdot 0)+32 ; & & \text { print } \mathrm{F} \\ \mathrm{C}=21.0 ; & \mathrm{F}=9.0 * \mathrm{C} / 5 \cdot 0+32 ; & & \text { print } \mathrm{F} \\ \mathrm{C}=21 ; & \mathrm{F}=9 * \mathrm{C} / 5+32 ; & & \text { print } \mathrm{F} \\ \mathrm{C}=21.0 ; & \mathrm{F}=(1 / 5) * 9 * \mathrm{C}+32 ; & & \text { print } \mathrm{F} \\ \mathrm{C}=21 ; & \mathrm{F}=(1 . / 5) * 9 * \mathrm{C}+32 ; & & \text { print } \mathrm{F} \end{array} $$

Short answer

Versions 4 and 8 will not work; version 4 has a syntax error, and version 8 has an incorrect division symbol.

Step-by-step solution

Identify Correct Formula

The correct formula for converting Celsius (C) to Fahrenheit (F) is:\[ F = \frac{9}{5} \times C + 32 \]

Analyze Each Line of Code

We'll evaluate each program line against the correct formula to see if it works correctly.

Step 2.1: First Version

Code: \( C=21; \ F=9/5 * C + 32; \ ext{print} \ F \)- The multiplication by \(\frac{9}{5}\) is correct. The integer division will work fine since it doesn't affect the result meaningfully due to order of operations. - Output will be the correct one.

Step 2.2: Second Version

Code: \( C=21.0; \ F=(9/5) * C + 32; \ ext{print} \ F \)- The use of parentheses ensures proper division. - Output will be correct.

Step 2.3: Third Version

Code: \( C=21.0; \ F=9 * C / 5 + 32; \ ext{print} \ F \)- Although the form changes, the operations still perform correctly. Multiplying first and then dividing will yield the same result as dividing and then multiplying.- Output will be correct.

Step 2.4: Fourth Version

Code: \( C=21.0; \ F=9 . * (C / 5 \cdot 0) + 32; \ ext{print} \ F \)- Syntax error due to the dot after '9'.- Code will not execute.

Step 2.5: Fifth Version

Code: \( C=21.0; \ F=9.0 * C / 5 \cdot 0 + 32; \ ext{print} \ F \)- Calculations will be flawed due to incorrect operations resulting in multiplication with zero, altering the expected result.- Code will execute but return an incorrect result.

Step 2.6: Sixth Version

Code: \( C=21; \ F=9 * C / 5 + 32; \ ext{print} \ F \)- Works similarly to the third version. Operations are performed correctly in terms of order, hence the output will be correct.

Step 2.7: Seventh Version

Code: \( C=21.0; \ F=(1/5) * 9 * C + 32; \ ext{print} \ F \)- The rearrangement still results in the same multiplication and division as in the original formula.- Output will be correct.

Step 2.8: Eighth Version

Code: \( C=21; \ F=(1 . / 5) * 9 * C + 32; \ ext{print} \ F \)- Syntax error: A dot is erroneously used, which may cause the code to not execute.

Key concepts

Celsius to Fahrenheit conversion

Converting temperatures from Celsius to Fahrenheit is a fundamental task in programming, especially when working with data in different scientific fields. The formula to convert Celsius (\( C \)) to Fahrenheit (\( F \)) is:
\[ F = \frac{9}{5} \times C + 32 \]
In this formula, you firstly multiply the Celsius value by \( \frac{9}{5} \) and then add 32 to the result to obtain the Fahrenheit temperature. This conversion is essential as it helps bridge different measurement systems used around the world.

• The formula uses a simple linear transformation which is part of basic arithmetic operations in Python.
• Due to the multiplication and addition involved, it is crucial to follow the correct order of operations to ensure accurate conversion.

Understanding how to correctly implement this formula in Python will enhance your ability to manage data involving temperature conversions.

Common programming errors

Programming errors can be a headache, but understanding common errors helps prevent them. One common error is the syntax error, which occurs when the code violates Python’s syntax rules.
For instance, in temperature conversion problems, a syntax error might occur due to unnecessary dots, like ```9 . /``` instead of ```9.0 /```, leading to issues with execution.

• Ensure each line of code follows correct Python syntax without unnecessary symbols.
• Check for common mistakes like missing parentheses in arithmetic operations.

Logical errors might not stop your code from running, but they can produce incorrect results, such as an incorrect multiplication leading to zero in formulas, which affects outputs. Thus, careful review of both syntax and logic is crucial for error-free programming.

Python syntax

Getting to grips with Python syntax is crucial for every programmer. Correct syntax ensures that your code runs smoothly without errors. In Python, syntax includes rules about how you must structure commands.

• Indentation is mandatory to define the scope in control structures, unlike other languages that use braces.
• Proper use of operators, like ensuring no unnecessary use of decimal points unless intended for floating-point operations, as seen in conversions, is crucial.
• Avoid using incorrect operators which might change operation order or result in syntax errors.

Adhering strictly to correct syntax not only keeps errors at bay but also improves code readability and maintainability. Keeping up with Python syntax evolution can further optimize the coding experience, leading to more efficient and error-free programming projects.

Python arithmetic operations

Arithmetic operations are at the core of many programming tasks in Python. Python supports standard operations such as addition, subtraction, multiplication, and division.
Temperature conversion exercises often include these operations. For example, converting Celsius involves:

• Multiplying with \( \frac{9}{5} \)
• Adding 32 afterward

Mastering these operations in Python requires understanding the order of operations, which follows PEMDAS (Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right)).
Python's operations work well with both integers and floating-point numbers. Precision can be essential in some calculations, especially when dealing with degrees and fractions. Ensuring correct order in these operations avoids inaccuracies in your results.