Explanations 
Flashcards 
StudySmarter AI 
Notes 
Study Plans 
Study Sets 
Exams 
Magazine 
Find a job 
Mobile App 
Jump to a key chapter
Tangent Rule in Mathematics
Understanding the tangent rule is an important step in enhancing your mathematical skills. It is particularly useful in the field of trigonometry and calculus.
Definition of the Tangent Rule
The tangent rule, also known as the tangent-sum formula, is a crucial trigonometric identity used to find the tangent of the sum or difference of two angles. It is expressed as:
For the sum of two angles, \[ \tan(A + B) = \frac{\tan A + \tan B}{1 - \tan A \tan B} \]
For the difference of two angles, \[ \tan(A - B) = \frac{\tan A - \tan B}{1 + \tan A \tan B} \]
How to Use the Tangent Rule
To effectively use the tangent rule, you need to follow a series of steps:
- Identify the angles involved in the problem.
- Determine whether you are dealing with the sum or difference of these angles.
- Apply the appropriate tangent formula.
- Simplify the expression to arrive at the solution.
Remember that the tangent rule only applies to angles measured in radians or degrees. Ensure you are consistent with your angle measurements.
Examples of the Tangent Rule
Example 1: Find the tangent of the sum of 30° and 45°.
Using the tangent rule:
\[ \tan(30° + 45°) = \frac{\tan 30° + \tan 45°}{1 - \tan 30° \tan 45°} \]
We know that \(\tan 30° = \frac{1}{\sqrt{3}}\) and \(\tan 45° = 1\), so:
\[ \tan(30° + 45°) = \frac{\frac{1}{\sqrt{3}} + 1}{1 - \frac{1}{\sqrt{3}} \cdot 1} \]
Simplify this to get:
\[ \tan 75° = \frac{\frac{1 + \sqrt{3}}{\sqrt{3}}}{\frac{\sqrt{3} - 1}{\sqrt{3}}} \]
Which simplifies further to:
\[ \tan 75° = \frac{1 + \sqrt{3}}{\sqrt{3} - 1} \]
Understanding the derivation of the tangent rule can provide a deeper appreciation for this formula. The tangent rule is derived using the sine and cosine addition formulas. For the sum:
\[ \sin(A + B) = \sin A \cos B + \cos A \sin B \]
\[ \cos(A + B) = \cos A \cos B - \sin A \sin B \]
Dividing these two equations gives:
\[ \frac{\sin(A + B)}{\cos(A + B)} = \frac{\sin A \cos B + \cos A \sin B}{\cos A \cos B - \sin A \sin B} \]
Since \( \frac{\sin(A + B)}{\cos(A + B)} = \tan(A + B)\), we arrive at the tangent-sum formula:
\[ \tan(A + B) = \frac{\tan A + \tan B}{1 - \tan A \tan B} \]
Definition of Tangent Rule
The tangent rule is an essential concept in trigonometry that helps in finding the tangent of the sum or difference of two angles. Whether you are solving complex equations or simple problems, this rule is highly valuable.
Definition of the Tangent Rule
The tangent rule, also known as the tangent-sum formula, is expressed as:For the sum of two angles, \[ \tan(A + B) = \frac{\tan A + \tan B}{1 - \tan A \tan B} \] For the difference of two angles, \[ \tan(A - B) = \frac{\tan A - \tan B}{1 + \tan A \tan B} \]
How to Use the Tangent Rule
To effectively use the tangent rule, follow these steps:
- Identify the angles involved in the problem.
- Determine whether you are dealing with the sum or difference of these angles.
- Apply the appropriate tangent formula.
- Simplify the expression to arrive at the solution.
Remember that the tangent rule only applies to angles measured in radians or degrees. Ensure you are consistent with your angle measurements.
Examples of the Tangent Rule
Example 1: Find the tangent of the sum of 30° and 45°.
Using the tangent rule:
\[ \tan(30° + 45°) = \frac{\tan 30° + \tan 45°}{1 - \tan 30° \tan 45°} \]
We know that \(\tan 30° = \frac{1}{\sqrt{3}}\) and \(\tan 45° = 1\), so:
\[ \tan(30° + 45°) = \frac{\frac{1}{\sqrt{3}} + 1}{1 - \frac{1}{\sqrt{3}} \cdot 1} \]
Simplify this to get:
\[ \tan 75° = \frac{\frac{1 + \sqrt{3}}{\sqrt{3}}}{\frac{\sqrt{3} - 1}{\sqrt{3}}} \]
Which simplifies further to:
\[ \tan 75° = \frac{1 + \sqrt{3}}{\sqrt{3} - 1} \]
Understanding the derivation of the tangent rule can provide a deeper appreciation for this formula. The tangent rule is derived using the sine and cosine addition formulas.For the sum:
\[ \sin(A + B) = \sin A \cos B + \cos A \sin B \]
\[ \cos(A + B) = \cos A \cos B - \sin A \sin B \]
Dividing these two equations gives:
\[ \frac{\sin(A + B)}{\cos(A + B)} = \frac{\sin A \cos B + \cos A \sin B}{\cos A \cos B - \sin A \sin B} \]
Since \( \frac{\sin(A + B)}{\cos(A + B)} = \tan(A + B) \), we arrive at the tangent-sum formula:
\[ \tan(A + B) = \frac{\tan A + \tan B}{1 - \tan A \tan B} \]
Tangent Rule Explained with Examples
Understanding the tangent rule is an integral part of enhancing your mathematical skills. This trigonometric identity is especially useful in solving problems related to the sum or difference of angles.
Definition of the Tangent Rule
The tangent rule, also known as the tangent-sum formula, is expressed as:
For the sum of two angles:
\[ \tan(A + B) = \frac{\tan A + \tan B}{1 - \tan A \tan B} \]
For the difference of two angles:
\[ \tan(A - B) = \frac{\tan A - \tan B}{1 + \tan A \tan B} \]
How to Use the Tangent Rule
To effectively use the tangent rule, follow these steps:
- Identify the angles involved in the problem.
- Determine whether you are dealing with the sum or difference of these angles.
- Apply the appropriate tangent formula.
- Simplify the expression to arrive at the solution.
Remember that the tangent rule only applies to angles measured in radians or degrees. Ensure you are consistent with your angle measurements.
Examples of the Tangent Rule
Example 1: Find the tangent of the sum of 30° and 45°.
Using the tangent rule:
\[ \tan(30° + 45°) = \frac{\tan 30° + \tan 45°}{1 - \tan 30° \tan 45°} \]
We know that \( \tan 30° = \frac{1}{\sqrt{3}} \) and \( \tan 45° = 1 \), so:
\[ \tan(30° + 45°) = \frac{\frac{1}{\sqrt{3}} + 1}{1 - \frac{1}{\sqrt{3}} \cdot 1} \]
Simplify this to get:
\[ \tan 75° = \frac{\frac{1 + \sqrt{3}}{\sqrt{3}}}{\frac{\sqrt{3} - 1}{\sqrt{3}}} \]
Which further simplifies to:
\[ \tan 75° = \frac{1 + \sqrt{3}}{\sqrt{3} - 1} \]
Understanding the derivation of the tangent rule can provide a deeper appreciation for this formula. The tangent rule is derived using the sine and cosine addition formulas.
For the sum:
\[ \sin(A + B) = \sin A \cos B + \cos A \sin B \]
\[ \cos(A + B) = \cos A \cos B - \sin A \sin B \]
Dividing these two equations gives:
\[ \frac{\sin(A + B)}{\cos(A + B)} = \frac{\sin A \cos B + \cos A \sin B}{\cos A \cos B - \sin A \sin B} \]
Since \( \frac{\sin(A + B)}{\cos(A + B)} = \tan(A + B) \), we arrive at the tangent-sum formula:
\[ \tan(A + B) = \frac{\tan A + \tan B}{1 - \tan A \tan B} \]
Tangent Rule in Trigonometry Techniques
The tangent rule is a powerful tool in trigonometry that allows you to calculate the tangent of the sum or difference of angles. Knowing how to apply this rule can simplify many trigonometric problems. Let's explore the tangent rule in detail.
Definition of the Tangent Rule
The \textbf{tangent rule}, or tangent-sum formula, is given by:
For the sum of two angles:
\[ \tan(A + B) = \frac{\tan A + \tan B}{1 - \tan A \tan B} \]
For the difference of two angles:
\[ \tan(A - B) = \frac{\tan A - \tan B}{1 + \tan A \tan B} \]
How to Use the Tangent Rule
To effectively use the tangent rule, follow these steps:
- Identify the angles involved in the problem.
- Determine whether you are dealing with the sum or difference of these angles.
- Apply the appropriate tangent formula.
- Simplify the expression to arrive at the solution.
Ensure that your angle measurements are consistent. The tangent rule applies to both radians and degrees.
Examples of the Tangent Rule
Example 1: Find the tangent of the sum of 30° and 45°.
Using the tangent rule:
\[ \tan(30° + 45°) = \frac{\tan 30° + \tan 45°}{1 - \tan 30° \tan 45°} \]
We know that \( \tan 30° = \frac{1}{\sqrt{3}} \) and \( \tan 45° = 1 \), so:
\[ \tan(30° + 45°) = \frac{\frac{1}{\sqrt{3}} + 1}{1 - \frac{1}{\sqrt{3}} \cdot 1} \]
Simplify this to get:
\[ \tan 75° = \frac{\frac{1 + \sqrt{3}}{\sqrt{3}}}{\frac{\sqrt{3} - 1}{\sqrt{3}}} \]
Which further simplifies to:
\[ \tan 75° = \frac{1 + \sqrt{3}}{\sqrt{3} - 1} \]
Understanding the derivation of the tangent rule can provide a deeper appreciation for this formula. The tangent rule is derived using the sine and cosine addition formulas.
For the sum:
\[ \sin(A + B) = \sin A \cos B + \cos A \sin B \]
\[ \cos(A + B) = \cos A \cos B - \sin A \sin B \]
Dividing these two equations gives:
\[ \frac{\sin(A + B)}{\cos(A + B)} = \frac{\sin A \cos B + \cos A \sin B}{\cos A \cos B - \sin A \sin B} \]
Since \( \frac{\sin(A + B)}{\cos(A + B)} = \tan(A + B) \), we arrive at the tangent-sum formula:
\[ \tan(A + B) = \frac{\tan A + \tan B}{1 - \tan A \tan B} \]
Tangent rule - Key takeaways
- Tangent Rule Definition: The tangent rule, also known as the tangent-sum formula, is a trigonometric identity used to find the tangent of the sum or difference of two angles.
- Sum Formula: For the sum of two angles, the tangent rule is expressed as: \( \tan(A + B) = \frac{\tan A + \tan B}{1 - \tan A \tan B} \).
- Difference Formula: For the difference of two angles, the tangent rule is given by: \( \tan(A - B) = \frac{\tan A - \tan B}{1 + \tan A \tan B} \).
- Usage Steps: Identify the angles, determine whether dealing with sum or difference, apply the appropriate tangent formula, and simplify the expression.
- Example Application: Finding \( \tan(30° + 45°) \) using the tangent rule results in \( \tan 75° = \frac{1 + \sqrt{3}}{\sqrt{3} - 1} \).
Learn faster with the 12 flashcards about Tangent rule
Sign up for free to gain access to all our flashcards.
Frequently Asked Questions about Tangent rule
About StudySmarter
StudySmarter is a globally recognized educational technology company, offering a holistic learning platform designed for students of all ages and educational levels. Our platform provides learning support for a wide range of subjects, including STEM, Social Sciences, and Languages and also helps students to successfully master various tests and exams worldwide, such as GCSE, A Level, SAT, ACT, Abitur, and more. We offer an extensive library of learning materials, including interactive flashcards, comprehensive textbook solutions, and detailed explanations. The cutting-edge technology and tools we provide help students create their own learning materials. StudySmarter’s content is not only expert-verified but also regularly updated to ensure accuracy and relevance.
Learn more