Last modified: Jan 14, 2025 By Alexander Williams

Python sympy.together() Guide: Simplify Rational Expressions

Python's SymPy library is a powerful tool for symbolic mathematics. One of its useful functions is sympy.together(). This function helps combine rational expressions into a single fraction.

In this guide, we'll explore how to use sympy.together() effectively. We'll also provide examples to help you understand its application in simplifying expressions.

What is sympy.together()?

The sympy.together() function is used to combine rational expressions into a single fraction. It is particularly useful when dealing with complex algebraic expressions.

This function works by finding a common denominator for the given expressions. It then combines them into a single fraction. This simplifies the expression, making it easier to work with.

How to Use sympy.together()

To use sympy.together(), you first need to import the SymPy library. Then, you can define your rational expressions and apply the function.

Here's a simple example:


import sympy as sp

# Define symbols
x = sp.symbols('x')

# Define rational expressions
expr1 = 1/x
expr2 = 1/(x + 1)

# Combine expressions using sympy.together()
combined_expr = sp.together(expr1 + expr2)

print(combined_expr)

In this example, we define two rational expressions: 1/x and 1/(x + 1). We then use sympy.together() to combine them into a single fraction.

Example Output

When you run the above code, you'll get the following output:


(2*x + 1)/(x*(x + 1))

This output shows the combined fraction. The numerator is 2*x + 1, and the denominator is x*(x + 1).

Advanced Usage

sympy.together() can also handle more complex expressions. For example, you can use it with trigonometric functions or exponential expressions.

Here's an example with trigonometric functions:


import sympy as sp

# Define symbols
x = sp.symbols('x')

# Define rational expressions with trigonometric functions
expr1 = sp.sin(x)/x
expr2 = sp.cos(x)/(x + 1)

# Combine expressions using sympy.together()
combined_expr = sp.together(expr1 + expr2)

print(combined_expr)

This code combines two rational expressions involving trigonometric functions. The output will be a single fraction combining these expressions.

Related Functions

SymPy offers several other functions that can help simplify expressions. For example, sympy.apart() can decompose a rational expression into partial fractions.

Another useful function is sympy.trigsimp(), which simplifies trigonometric expressions. These functions can be used in conjunction with sympy.together() for more advanced symbolic math tasks.

Conclusion

The sympy.together() function is a valuable tool for simplifying rational expressions in Python. It combines multiple fractions into a single fraction, making complex expressions easier to handle.

By mastering sympy.together(), you can streamline your symbolic math workflows. Whether you're working with simple or complex expressions, this function can save you time and effort.

For more advanced techniques, consider exploring other SymPy functions like sympy.sympify() and sympy.Rational(). These tools can further enhance your symbolic math capabilities.