What is the definition of trigonometric function with four acute angles required in senior high school mathematics? Ask for a detailed explanation! ! Later inductive formulas cannot be used. - Training Enrollment Network

What is the definition of trigonometric function with four acute angles required in senior high school mathematics? Ask for a detailed explanation! ! Later inductive formulas cannot be used.

As I am a high school student, I can't understand trigonometric functions only in right triangles, but in coordinate axes.

Let A(x,

y),x^2+y^2=r^2

sinα=y/r

cosα=x/r

tanα=y/x

So we can understand the symbols of trigonometric functions on each coordinate axis.

There are positive, negative and positive sins.

Cos is positive, negative and positive.

Tan is affirmative and negative.

As for sin(α+π/2) and sin(α+π/4), the result is "parity unchanged, sign according to quadrant".

Related articles

Mathematics and applied mathematics employment direction

There are more and more female teachers and fewer and fewer male teachers. What is the reason?

I am a repeat student in the college entrance examination, majoring in liberal arts. There are still 180 days before the college entrance examination. What should I do to score? Mentioned above 540 po

What does number theory include?

What is the edition of Anhui primary school mathematics textbook?

Teaching Plan of "Interesting Sorting" in Large Class Mathematics Activities

Which is more difficult, the pyramids or the Temple of Heaven?

Excuse me, what are the application questions about perimeter and area in the second volume of mathematics in the third grade of primary school?

Come to primary school mathematics