geeksforgeeks.org

Trigonometric Ratios Table: Easy Steps to Create Your Own

Curated by

cdteliot

8 min read

1,125

A trigonometry table is a fundamental tool in mathematics that provides values for trigonometric functions such as sine, cosine, and tangent for standard angles. This essential reference, which typically includes angles from 0° to 90°, aids in solving trigonometric problems and has applications in various fields including navigation, engineering, and physics.

## Comprehensive Trigonometric Table Overview

The trigonometric table from 0° to 360° provides values for all six trigonometric functions (sine, cosine, tangent, cotangent, secant, and cosecant) across the full circle. This comprehensive table is essential for solving problems involving angles beyond the first quadrant.

This table is crucial for various applications in mathematics, engineering, and physics. It allows for quick reference of trigonometric values at standard angles, facilitating calculations in fields such as navigation, astronomy, and signal processing

Angle (°) | Sin | Cos | Tan | Cot | Sec | Cosec |
---|---|---|---|---|---|---|

0° | 0 | 1 | 0 | ∞ | 1 | ∞ |

30° | 1/2 | √3/2 | 1/√3 | √3 | 2/√3 | 2 |

45° | 1/√2 | 1/√2 | 1 | 1 | √2 | √2 |

60° | √3/2 | 1/2 | √3 | 1/√3 | 2 | 2/√3 |

90° | 1 | 0 | ∞ | 0 | ∞ | 1 |

180° | 0 | -1 | 0 | ∞ | -1 | ∞ |

270° | -1 | 0 | ∞ | 0 | ∞ | -1 |

360° | 0 | 1 | 0 | ∞ | 1 | ∞ |

1

2

3

.5 sources

## Essential Trigonometric Formulas

Before delving into complex trigonometric problems, it's essential to familiarize yourself with these fundamental trigonometric formulas. These relationships form the basis for many trigonometric calculations and identities:

- sin x = cos (90° – x)
- cos x = sin (90° – x)
- tan x = cot (90° – x)
- cot x = tan (90° – x)
- sec x = cosec (90° – x)
- cosec x = sec (90° – x)
- 1/sin x = cosec x
- 1/cos x = sec x
- 1/tan x = cot x

2

.5 sources

## Understanding Trigonometric Ratios Table (Videos)

youtube.com

Watch

youtube.com

Watch

## 1. Creating Your Own Trigonometric Ratios Table: Calculating Sine Values

To determine the sine values for standard angles, a simple method can be used. This method involves dividing integers by 4 under a square root. Here's how it works:

For angles beyond 90°, we use the following relationships: sin(180° - x) = sin x, sin(180° + x) = -sin x, and sin(360° - x) = -sin x. This method provides a quick way to determine sine values for standard angles without memorizing each individual value.

Angle | Calculation | Sine Value |
---|---|---|

0° | √(0/4) | 0 |

30° | √(1/4) | 1/2 |

45° | √(2/4) | 1/√2 |

60° | √(3/4) | √3/2 |

90° | √(4/4) | 1 |

1

2

5 sources

## 2. Creating Your Own Trigonometric Ratios Table: Calculating Cosine Values

Calculating cosine values for standard angles follows a pattern complementary to sine values. This method involves dividing integers by 4 under a square root, but in reverse order compared to sine calculations.

For angles beyond 90°, we use the relationships: cos(180° - x) = -cos x, cos(180° + x) = -cos x, and cos(360° - x) = cos x. This method provides a systematic way to determine cosine values for standard angles, complementing the sine value calculations.

Angle | Calculation | Cosine Value |
---|---|---|

0° | √(4/4) | 1 |

30° | √(3/4) | √3/2 |

45° | √(2/4) | 1/√2 |

60° | √(1/4) | 1/2 |

90° | √(0/4) | 0 |

1

2

3

5 sources

## 3. Creating Your Own Trigonometric Ratios Table: Calculating Tangent Values

Calculating tangent values for standard angles involves using the relationship between sine and cosine. The tangent of an angle is defined as the ratio of its sine to its cosine (tan θ = sin θ / cos θ).

This table provides tangent values for angles from 0° to 360°. Note that tangent is undefined at 90° and 270° as the cosine value is zero, resulting in division by zero.

Angle | Calculation | Tangent Value |
---|---|---|

0° | 0 / 1 | 0 |

30° | (1/2) / (√3/2) | 1/√3 |

45° | (1/√2) / (1/√2) | 1 |

60° | (√3/2) / (1/2) | √3 |

90° | 1 / 0 | ∞ (undefined) |

180° | 0 / -1 | 0 |

270° | -1 / 0 | ∞ (undefined) |

360° | 0 / 1 | 0 |

1

2

5 sources

## 4. Creating Your Own Trigonometric Ratios Table: Calculating Cotangent Values

Cotangent values are calculated as the reciprocal of tangent values for standard angles. This relationship is expressed as cot θ = 1 / tan θ, or equivalently, cot θ = cos θ / sin θ.

This table provides cotangent values for angles from 0° to 360°. Note that cotangent is undefined at 0°, 180°, and 360° as the tangent value is zero, resulting in division by zero

Angle | Calculation | Cotangent Value |
---|---|---|

0° | 1 / 0 | ∞ (undefined) |

30° | 1 / (1/√3) | √3 |

45° | 1 / 1 | 1 |

60° | 1 / √3 | 1/√3 |

90° | 1 / ∞ | 0 |

180° | 1 / 0 | ∞ (undefined) |

270° | 1 / ∞ | 0 |

360° | 1 / 0 | ∞ (undefined) |

5

.5 sources

## 5. Creating Your Own Trigonometric Ratios Table: Calculating Cosecant Values

Cosecant values are calculated as the reciprocal of sine values for standard angles. This relationship is expressed as cosec θ = 1 / sin θ.

This table provides cosecant values for angles from 0° to 360°. Note that cosecant is undefined at 0°, 180°, and 360° as the sine value is zero, resulting in division by zero

Angle | Calculation | Cosecant Value |
---|---|---|

0° | 1 / 0 | ∞ (undefined) |

30° | 1 / (1/2) | 2 |

45° | 1 / (1/√2) | √2 |

60° | 1 / (√3/2) | 2/√3 |

90° | 1 / 1 | 1 |

180° | 1 / 0 | ∞ (undefined) |

270° | 1 / (-1) | -1 |

360° | 1 / 0 | ∞ (undefined) |

1

2

.5 sources

## 6. Creating Your Own Trigonometric Ratios Table: Calculating Secant Values

Secant values are calculated as the reciprocal of cosine values for standard angles. This relationship is expressed as sec θ = 1 / cos θ.

This table provides secant values for angles from 0° to 360°. Note that secant is undefined at 90° and 270° as the cosine value is zero, resulting in division by zero.

Angle | Calculation | Secant Value |
---|---|---|

0° | 1 / 1 | 1 |

30° | 1 / (√3/2) | 2/√3 |

45° | 1 / (1/√2) | √2 |

60° | 1 / (1/2) | 2 |

90° | 1 / 0 | ∞ (undefined) |

180° | 1 / (-1) | -1 |

270° | 1 / 0 | ∞ (undefined) |

360° | 1 / 1 | 1 |

2

4

5 sources

## Trigonometric Function Values (Image)

cuemath.com

## Mastering Trigonometry: Sum and Difference Formulas Explained

The sum and difference formulas in trigonometry are essential tools for calculating trigonometric functions of complex angles. These formulas allow us to express the sine, cosine, and tangent of sums or differences of angles in terms of the trigonometric functions of the individual angles. The key formulas are:
$\sin(A+B)=\sin A\cos B+\cos A\sin B$

$\sin(A-B)=\sin A\cos B-\cos A\sin B$

$\cos(A+B)=\cos A\cos B-\sin A\sin B$

$\cos(A-B)=\cos A\cos B+\sin A\sin B$

$\tan(A+B)=\frac{\tan A+\tan B}{1-\tan A\tan B}$

$\tan(A-B)=\frac{\tan A-\tan B}{1+\tan A\tan B}$ These formulas are particularly useful for finding trigonometric values of non-standard angles by breaking them down into combinations of known angles. For example, to calculate sin 75°, one can use the sum formula with A = 30° and B = 45°, as these are common angles with known values in the trigonometric table

$\sin(A-B)=\sin A\cos B-\cos A\sin B$

$\cos(A+B)=\cos A\cos B-\sin A\sin B$

$\cos(A-B)=\cos A\cos B+\sin A\sin B$

$\tan(A+B)=\frac{\tan A+\tan B}{1-\tan A\tan B}$

$\tan(A-B)=\frac{\tan A-\tan B}{1+\tan A\tan B}$ These formulas are particularly useful for finding trigonometric values of non-standard angles by breaking them down into combinations of known angles. For example, to calculate sin 75°, one can use the sum formula with A = 30° and B = 45°, as these are common angles with known values in the trigonometric table

4

. This approach significantly expands the range of angles for which exact trigonometric values can be calculated, enhancing problem-solving capabilities in trigonometry and related fields such as physics and engineering.5 sources

## Mastering Trigonometry: Understanding Double Angle Formulas

Double angle formulas are specialized trigonometric identities that express trigonometric functions of double angles (2θ) in terms of functions of the single angle (θ). The key double angle formulas are:
$\sin 2θ=2\sin θ\cos θ$

$\cos 2θ=\cos^2θ-\sin^2θ=2\cos^2θ-1=1-2\sin^2θ$

$\tan 2θ=\frac{2\tan θ}{1-\tan^2θ}$ These formulas are derived from the sum formulas by setting both angles equal to θ

$\cos 2θ=\cos^2θ-\sin^2θ=2\cos^2θ-1=1-2\sin^2θ$

$\tan 2θ=\frac{2\tan θ}{1-\tan^2θ}$ These formulas are derived from the sum formulas by setting both angles equal to θ

1

. For example, the sine double angle formula is obtained by substituting A = B = θ in the sine sum formula2

. Double angle formulas are particularly useful for simplifying trigonometric expressions, solving equations, and finding exact values of trigonometric functions for certain angles3

. They also serve as a foundation for deriving other trigonometric identities and are widely applied in various fields of mathematics and physics4

5

.5 sources

## Closing Thoughts on Trigonometric Ratios Table

Trigonometric ratios tables serve as invaluable tools for solving triangle problems and understanding trigonometry functions. These tables for trigonometry provide quick access to values of sine, cosine, tangent, and their reciprocal functions for standard angles, eliminating the need for complex calculations or reliance on calculators

1

. By presenting a comprehensive table of values, they facilitate conceptual understanding of trigonometry ratios and their relationships to triangle sides, including the hypotenuse2

. While modern calculators can compute these values instantly, mastering trigonometry formulas and understanding how to use these tables enhances problem-solving skills and deepens knowledge of fundamental trigonometric concepts4

. Simple steps and rules for using these tables, combined with practice questions, can lead to correct answers and improved proficiency in applying trigonometry to real-world scenarios3

. Ultimately, a strong grasp of trigonometric ratios and their tabular representations forms the foundation for advanced mathematical and scientific pursuits.5 sources

Related

How can I use a trigonometric table to solve problems involving right triangles

What are the key patterns in trigonometric ratios that can help with memorization

Why are some trigonometric values undefined or infinite

How do complementary angles relate to trigonometric tables

What are the benefits of using a trigonometric table in physics and engineering