explain me basics of trigonometry
Answers
There are 6 thetas :-
sin¤ ,cos ¤ , tan¤, cosec¤, sec¤ ,cot¤
sin¤=1/coesc¤
cos¤=1/sec¤
tan¤=1/cot¤
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Now you should know about the trigonometric identies
sin²¤+ cos²¤ = 1
1+tan²¤=1
1+cot²¤=cosec²¤
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Formulas:-
Sin(A+B)= SinA cosB + cosA sinB
Sin(A-B) =SinA CosB - CosA SinB
Cos(A+B)=CosA cosB - SinA SinB
Cos(A-B) = CosA cosB + SinA SinB
Its a basic you can solve sum by applying these formulas
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Other Formulas:-
SinA + SinB = 2 sin(A +B) /2 into cos( A-B)/2
Sin A - Sin B = 2 cos (A +B) /2 into sin(A-B) /2
CosA +CosB=2 cos (A+B)/2 into Cos(A-B) /2
CosA-CosB= - 2 sin (A+B)/2 into sin(A-B) /2
Trigonometry, as the name might suggest, is all about triangles.
More specifically, trigonometry is about right-angled triangles, where one of the internal angles is 90°. Trigonometry is a system that helps us to work out missing sides or angles in a triangle.
There is more about triangles on our page on Polygons should you need to brush up on the basics before you read further here.
Right-Angled Triangles: A Reminder
A right-angled triangle has a single right angle. By definition, that means that all sides cannot be the same length. A typical right-angled triangle is shown below.
Important Terms for Right-Angled Triangles
Right-angled triangle showing the Opposite, Adjacent and Hypotenuse
The right angle is indicated by the little box in the corner.
The other angle that we (usually) know is indicated by θ.
The side opposite the right angle, which is the longest side, is called the hypotenuse.
The side opposite θ is called the opposite.
The side next to θ which is not the hypotenuse is called the adjacent.
Introducing Sine, Cosine and Tangent
There are three basic functions in trigonometry, each of which is one side of a right-angled triangle divided by another.
The three functions are:
Name Abbreviation Relationship to sides of the triangle
Sine Sin Sin (θ) = Opposite/hypotenuse
Cosine Cos Cos (θ) = Adjacent/hypotenuse
Tangent Tan Tan (θ) = Opposite/adjacent
Calculating Sine, Cosine and Tangent
You may find it helpful to remember Sine, Cosine and Tangent as SOH CAH TOA.