How do you remember the formula for the triogomentric functions?

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neela's profile pic

neela | High School Teacher | (Level 3) Valedictorian

Posted on

The trigonometric functions sinex , cosinex and tangentx and the respective  reciprocals  cosecant x , secant x and cotangent x, where x is the angle other than the right angle.

To remember easily these functios are expressed interms of the sides right angled triangle.

Let ABC be right angled triangle with right angle at B. Letanle A = x.

Then sine A = Sine x = BC/AC = Opposite side/Hypotenuse.

cosineA  = cosx = AB/AC =  Adjacent side /Hypotenuse

tanA = tanx = sinx/cosx  = BC/AB= Opposite side/ Adjacent side.

cosecantA = cosecantx = 1/sinex =AC/AB

secantA = 1/cosinex = AC/AB

cotangentx = 1/tangentx = AB/BC.

Thus the trigonometric functions could be easily remembered and calculated  through the sides of the right angled triangle at least roughly.

giorgiana1976's profile pic

giorgiana1976 | College Teacher | (Level 3) Valedictorian

Posted on

We'll consider the right angled triangle, whose hypothenuse is the radius of the trigonometric circle.

The radius of trigonometric circle is R = 1 unit and the x and y axis have the origin in the center of trigonometric circle.

We'll express the trigonometric functions, sine and cosine:

sin a = opposite cathetus/hypothenuse

sin a = y/R

sin a = y/1

sin a = y

cos a = x/R

cos a = x

We notice that the functions sine and cosine could be expressed with respect to the x and y axis.

kharsa's profile pic

kharsa | Student | (Level 1) Salutatorian

Posted on

A Cat Sat

On An Orange

And Howled Horribly

you use the above statment and you place it in this way so it becomes for cos which is cat = adjacent which is an divided by Hypotenuse which is howled

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