Cosine theorem sine theorem tangent theorem

Cosine theorem sine theorem tangent theorem

[in right angles]
Cosine of an angle = adjacent edge than hypotenuse
Sine of an angle = opposite side than bevel side
The tangent of an angle = opposite edge than adjacent edge

What's the use of the tangent theorem? Can you find the tangent value or the length of the side

Trigonometric function sine, cosine, tangent, Cotangent are based on the angle of the side length relationship, they are not only useful in the trigonometric function course, in the future plane geometry, solid geometry are very important! These must be grasped firmly, and will be used a lot later!

Metric theorem of protractor

When a flat angle (180 degrees) is divided into 180 parts or 180 × n (n is a natural number), the angle represented by each part can be determined. When one side of the angle to be measured coincides with the zero scale mark of the goniometer and its vertex coincides with the top point (middle point) of the goniometer, the other side of the angle to be measured coincides with the zero scale mark of the goniometer

This is the counter top angle protractor. Can you tell me the principle of measuring angle?

Where is the diagram? It uses the principle of equal vertex angles. Angle 1 + angle 2 is 180 ° and angle 2 + angle 3 is 180 ° which is equal to the two complementary angles of the same angle. I have attached a picture for you and hope it can help you

This is a counter top angle protractor. Can you tell me the principle of measuring angle with it

Where is the picture?
The principle of equal vertex angles is used. Angle 1 + angle 2 is 180 ° and angle 2 + angle 3 is 180 ° which is equal to two complementary angles of the same angle
I've got a picture for you

A protractor can measure ()

The size of the angle

Tangent theorem of higher one In △ ABC, ∠ a = 60 ° 3C = 4b, find sinc (specific process)

cosA=(b^2+c^2-a^2)/(2bc)=(25c^2/16-a^2)/(3c^2/2)=1/2
13c^2/16=a^2
A / Sina = C / sinc Sina = radical 3 / 2
Sinc = 2 * radical 39 / 13

On the theorem of tangent Cotangent, there is a theorem called "Junzi",

Mean value theorem
The premise a and B are positive numbers
Theorem a + b > = 2 roots AB if and only if a = B, the inequality takes the equal sign
Prove (root a-root b) ^ 2 〉 = 0
Then a + B-2 root AB 〉 = 0
So a + b > = 2 ab if and only if a = B
So, for a number and its reciprocal
1) When it is positive, x + 1 / x > = 2 roots x * 1 / x = 2 if and only if x = 1
2) When it is negative, x + 1 / x = - [(- x) + (1 / - x)]

When measuring angles with a protractor, one side of the angle should be the same as that of the protractor___ Coincide, the vertex of the angle should be the same as that of the protractor___ Coincide

When measuring angle with protractor, one side of the angle should coincide with the zero scale mark of the protractor, and the vertex of the angle should coincide with the center point of the protractor;
So the answer is: zero mark, center point

Sin30 degrees / 1 + sin60 degrees + 1 / tan30 degrees How to calculate the steps now very puzzled is 1 divided by 3 / 3 root 3, why root 3

1/2/(1+√3)+1/(√3/3)
=2-√3+3/√3
=2
1/(√3/3)=3/√3=√3