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Trigonometric Ratios

In this article, we will discuss about the trigonometric ratios of standard angles.

Trigonometric ratios are the ratios of the lengths of the triangle’s sides. Sin, cos, and tan, or sine, cosine, and tangent ratios, are the basic trigonometric ratios. The sin, cos, and tan, respectively, can be used to get the other trigonometric ratios, cosec, sec, and cot. 

The word “trigonometry” comes from the Greek words “trigonon” (meaning “triangle”) and “metron” (meaning “to measure.” It’s a branch of mathematics that deals with the relationship between a right-angled triangle’s angles and sides. In reality, trigonometry is one of the oldest sciences studied by academics all over the world.

Trigonometric Ratios

Sine, cosine, tangent, secant, cosecant, and cotangent are the six trigonometric ratios in trigonometry. In summary, these ratios are sin, cos, tan, sec, cosec and cot. Trigonometric ratios can be used to calculate the ratios of any two of a right-angled triangle’s three sides in terms of their respective angles.

In the right-angled triangle shown below, the values of these trigonometric ratios can be computed using the measure of an acute angle. This means that the value of the ratio of any two triangle sides is determined by angle. Alternatively, the values of these trig ratios for angle can be found.

The following are the six Trigonometric Ratios

  • The sine ratio is defined as the ratio of the perpendicular to the hypotenuse for any given angle. 

  • The cosine ratio is defined as the ratio of the base to the hypotenuse for any given angle. 

  • The tangent ratio is defined as the ratio of the perpendicular to the base for any given angle. 

  • The cosecant ratio is defined as the ratio of the hypotenuse to the perpendicular for any given angle. 

  • The secant ratio is defined as the ratio of the hypotenuse to the base for any given angle. 

  • The cotangent ratio is defined as the ratio of the base to the perpendicular for any given angle. 

Standard Angles of Trigonometric Ratios

The trigonometric table is essentially a tabular collection of values for trigonometric functions of various standard angles such as 0°, 30°, 45°, 60°, and 90°, as well as unusual angles such as 180°, 270°, and 360°. Because of the patterns that exist within trigonometric ratios and even between angles, it is simple to forecast the values of the trig ratios in a trigonometric table and use the trigonometric table for calculating trigonometric values for various other angles.

Trigonometric ratios – sine, cosine, tangent, cosecant, secant, and cotangent – are listed in the table.These ratios are in the table are written as  Sin, cos, tan, cosec, sec, and cot. The trigonometric ratios of these standard angles are the most easily recalled. To obtain the value of any trigonometric ratio for a given angle, a trigonometric table is employed. Trigonometric ratios of other angles can be calculated using the basic values of trig ratios for standard angles found in a trigonometry table. These values are used in industries like engineering and architecture.

In order to answer trigonometrical problems, the values of trigonometrical ratios of standard angles are crucial. The standard angles’ sine, cosine, and tangent are listed in the table below.

The trigonometric table has a few crucial points that should be noted:

Complementary angles in a trigonometric table, such as 30° and 60°, can be determined using complementary formulas for the various trigonometric ratios.

In a trig table, the value for various ratios is stated as or “not defined.” The reason for this is that when the values are computed, a “0” occurs in the denominator, making the value undefined and equivalent to infinity.

For values of particular trig ratios in a trigonometry table, there is a sign change at various places under 180°, 270°, and so on.

Important Trigonometric Table Notes

  • The three major trigonometric ratios: Sine, Cosine, and Tangent, are used to calculate trigonometric values.

  • The standard angles in trigonometry are 0 degree, 30 degree, 45 degree, 60 degree, and 90 degree in a trigonometric table.

  • These standard angles values of sine, cosecant, and tangent can also be used to determine the angle values of trigonometric functions cotangent, secant, and cosecant in a trigonometric table.

  • Higher angle values of trigonometric functions, such as 120 degree, 390 degree, and so on, can be easily calculated using standard angle values from a trigonometry table.

Conclusion

The ratios of the lengths of the triangle’s sides are known as trigonometric ratios. The basic trigonometric ratios are sin, cos, and tan, or sine, cosine, and tangent ratios.

Finding trigonometric ratios at different values is usually done with a calculator. However, if the problem involves some conventional angles, it may be necessary to solve it without using a calculator. The standard angles are 0 degrees, 30 degrees, 45 degrees, 60degrees, and 90 degrees.

 
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