Trig Functions table wgu pre calc task 1 reference notes

Trigonometric Functions Table
Function
Right Triangle Definition
Unit Circle Definition
Sine
Sine of theta is opposite over hypotenuse Sin θ =o/h
A unit circle is a circle with a radius of 1. In a unit circle sine of θ = y/r. r =1 so sin θ= y

Cosine
Cosine of theta is adjacent over hypotenuse Cos θ =a/h
A unit circle is a circle with a radius of 1. In a unit circle, cosine of θ = x/r. r = 1 sp cos θ = x

Tangent
Tangent of theta is opposite over adjacent Tan θ =o/a
A unit circle is a circle with a radius of 1. In a unit circle, tangent of θ = y/x. X cannot equal 0 because that is undefined

Cosecant
Cosecant is the reciprocal of sine. Cosecant, represented by abbreviation csc, is hypotenuse over opposite csc θ =h/o
In a unit circle, cosecant is the reciprocal of sine so sin θ = r/y. Y cannot equal 0 because that is undefined. So, csc θ = 1/y
Secant
Secant is the reciprocal of cosine. Secant is represented by the abbreviation sec, and is equal to hypotenuse over adjacent. Sec=h/a
In a unit circle, secant is the reciprocal of cosine so csc θ = r/x x cannot = 0 because that is undefined. So, sec θ = 1/x
Cotangent
Cotangent is the reciprocal of tangent, represented by the abbreviation cot. Cotangent of theta is equal to adjacent over opposite. Cot θ =a/h
In a unit circle, cotangent is the reciprocal of tangent so cot θ = x/y again, Y cannot = 0 because that would make it undefined.