The concept of mathematical trigonometric functions sine, cosine, secant, coecant, tangent, cotangent, cotangent in depth The source of the name in the unit circle indicates that there is a similarity between sine and cosmos + chord cleavage: from the Pythagorean theorem can be deduced:
After entering high school, students will begin to learn the knowledge of trigonometric functions.
There are six trigonometric functions in total:
sin, cosine;
Tangent (tan), cotangent (cot);
Positive discount (sec), remainder (cosec).
Many students feel that after learning it, it is a word - around.
The relationship between these six trigonometric functions is indeed too winding. Today [Ten Times Teacher] will take a deep look at them for everyone.
<h1 class="pgc-h-arrow-right" > the origin of the name</h1>
The concept of mathematical trigonometric functions sine, cosine, secant, coecant, tangent, cotangent, cotangent in depth The source of the name in the unit circle indicates that there is a similarity between sine and cosmos + chord cleavage: from the Pythagorean theorem can be deduced:
Positive and cognux angles
The naming principle of positive and yu:
In a unit circle, the angle AOB is a positive angle; the angle BOE is the cogener angle. These two corners are redundant. The inferior arc AB is the arc paired by the positive angle AOB, which we call the positive arc, and the arc paired by the cohom angle BOE is the coherent arc.
The naming principle of strings, cuts, and cuts:
Chord understanding
Connect two fixed-point segments
The concept of mathematical trigonometric functions sine, cosine, secant, coecant, tangent, cotangent, cotangent in depth The source of the name in the unit circle indicates that there is a similarity between sine and cosmos + chord cleavage: from the Pythagorean theorem can be deduced:
Cut understanding
Cut along the edges
The concept of mathematical trigonometric functions sine, cosine, secant, coecant, tangent, cotangent, cotangent in depth The source of the name in the unit circle indicates that there is a similarity between sine and cosmos + chord cleavage: from the Pythagorean theorem can be deduced:
Understanding of secant lines
The meaning of severing and dividing
The concept of mathematical trigonometric functions sine, cosine, secant, coecant, tangent, cotangent, cotangent in depth The source of the name in the unit circle indicates that there is a similarity between sine and cosmos + chord cleavage: from the Pythagorean theorem can be deduced:
<h1 class="pgc-h-arrow-right" > represent positive and cov + chord cut in the unit circle</h1>
The concept of mathematical trigonometric functions sine, cosine, secant, coecant, tangent, cotangent, cotangent in depth The source of the name in the unit circle indicates that there is a similarity between sine and cosmos + chord cleavage: from the Pythagorean theorem can be deduced:
Sine + Sine + Seisada + Sadashi
The concept of mathematical trigonometric functions sine, cosine, secant, coecant, tangent, cotangent, cotangent in depth The source of the name in the unit circle indicates that there is a similarity between sine and cosmos + chord cleavage: from the Pythagorean theorem can be deduced:
Cosine + Superfluous + Extra Cut
From these lengths, two triangles can be constructed separately, which I call positive triangles and cognizant triangles. As shown in the figure:
The concept of mathematical trigonometric functions sine, cosine, secant, coecant, tangent, cotangent, cotangent in depth The source of the name in the unit circle indicates that there is a similarity between sine and cosmos + chord cleavage: from the Pythagorean theorem can be deduced:
Positive and cognizant triangles
These two triangles are similar to each other.
The concept of mathematical trigonometric functions sine, cosine, secant, coecant, tangent, cotangent, cotangent in depth The source of the name in the unit circle indicates that there is a similarity between sine and cosmos + chord cleavage: from the Pythagorean theorem can be deduced:
<h1 class="pgc-h-arrow-right" > similarities can be deduced:</h1>
<h1 class="pgc-h-arrow-right" > can be deduced from the Pythagorean theorem:</h1>
Square of tangent + square of radius (1) = square of secant
The square of the cotangent + the square of the radius (1) = the square of the co-cut
The concept of mathematical trigonometric functions sine, cosine, secant, coecant, tangent, cotangent, cotangent in depth The source of the name in the unit circle indicates that there is a similarity between sine and cosmos + chord cleavage: from the Pythagorean theorem can be deduced:
Large diagram of trigonometric functions
The graphics in this article are drawn using GeoGebra
It is not appropriate to write, and I hope that all the officials will casually give a thumbs up.
