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Trigonometry is an important branch of mathematics that is related to the measurement of sides and angles of a triangle and how they are related to each other.  When you start to learn about any branch of mathematics, you always need to start with the basic terms, functions or formulas. Trigonometry starts with Trigonometry Functions and Trigonometry identities.

There are six basic terms in trigonometry that you will encounter while solving any problem of trigonometry. These terms are sin A, cos A, tan A, cosec A, sec A and cot A (A stands of any angle between 0 degree and 90 degrees). Each of these terms is equal to the ratio of two specific sides of a right triangle. It is important to note that the trigonometric functions are defined for a right triangle. A right triangle is a special case of a triangle with one right angle. Since the sum of three sides of a triangle is always equals to 180 degrees, the other two angles must add up to give 90 degrees. Hence, the other two angles are acute angles (angles measuring between 0 degree and 90 degrees). Once you know How to Remember Trigonometric Functions, you can learn about the trigonometric identities.

Trigonometric Functions

There are six trigonometric functions. The first three functions express the terms sin A, cosA and tan A in terms of the ration of sides of a right triangle with one of the acute angles marked as A. Let us consider a right triangle as shown below with A, B and C as angles at each vertex and a, b and c as the length of sides opposite to them respectively.
For angle A,

sin A = =

cos A = =

tan A = =

The simplest and the most widely used trick to remember the first three Trigonometric Functions is to remember Soh Cah Toa. Just repeat it a few times and it will get into your mind.

S = sin
C =cos
T = tan
o = opposite side
h = hypotenuse

With the next trick, you will not have to worry about How to Remember Trigonometric Functions.

The next three trigonometric functions are:

cosec A =

sec A =

cot A =

The last term is easy to remember as the cot and tan sound similar. However, cosec sounds similar to cos and sec sounds similar to sin. Here you need to remember is that cosec and sec must be matched with terms that do not sound similar to them.

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