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Is there any way to calculate the value of special angle function? What degree is cos 82.8; Cos 42.3; Cos 0.725; Cos 0.9086?
The so-called special angle is the angle that can be related to 30,60,90. If it is the type of cosa = 0.725, we can calculate the degree of 15 ° and 45 ° which is usually the angle we often encounter when we do problems, or the common right triangle (side is 3,4,5 or 5,12,13, etc.)
You can use a calculator to calculate and remember when you have nothing to do
cos 82.8=0.1253（33233564304）；cos42.3=0.7396（3109497861）；（cos）-1 0.725=43.53°；（cos）-1 0.9086=24.6874°
Right triangle function problem In the right triangle ABC, ∠ C = 90 ° if AB = 4, BC = 2, radical 3, then a Cos - how much is cos Two There are the following options A. root 3 / 2 b. root 3 / 3 C. root 3 d. 2 - root 3 I calculated that cosa = 1 / 2, that is 1 / 4, but why not cosa is equal to 1 / 2
In the right triangle ABC, ab = 4, BC = 2 √ 3, the result is: a = 60 ° cosa = 1 / 2
Cosa / 2 = cos30 = √ 3 / 2 (√: root sign)
Are ortho functions and cosine functions only used on right triangles
In high school, the definition of trigonometric function is in a unit circle
There are also some formulas, such as the sine theorem: A / Sina = B / SINB = C / sinc = 2R in a triangle
Cosine theorem: A ^ 2 = B ^ 2 + C ^ 2-2bc * cosa
There are also some trigonometric transformations often used in evaluation and proof
What is the function of the opposite side of a right triangle to its adjacent side? If the opposite side is 10 mm and the adjacent side is 273 mm, what is the angle to 10 mm? If the opposite side is 10 and the hypotenuse is 273, what is the angle?
The opposite side is tan, which is the tangent function
If we take the angle, it's arctan (10 / 273)
For a right triangle with an angle of 60 degrees, the relation between its area y and its hypotenuse x is? As the title
The square of y = 0.5 ×√ 0.75 × x
√ stands for radical
For a right triangle of area 10, the center line of the hypotenuse is x, and the height of the hypotenuse is y For a right triangle of area 10, the center line of the hypotenuse is x and the height of the hypotenuse is y Find (1) the functional relationship between Y and X (2) write the value range of independent variable x (3) when x = 5, find the value of Y
The center line on the hypotenuse of a right triangle is equal to half of the hypotenuse
The center line of the hypotenuse is X
The slant side length is 2x
The height of the hypotenuse is y
∴S=1/2*(2X)*Y=XY=10
∴Y=10/X
The vertical distance from a point outside the line to the straight line is the shortest, ﹥ y ≤ X
Again: xy = 10
∴X^2≥10
ν x ≥ √ 10, that is, X ∈ (√ 10, + ∞)
When x = 5, y = 10 / 5 = 2
For a right triangle with an area of 10 and a 30 ° angle, the length of the shortest side is x, and the height of the hypotenuse is y. write the functional relationship between Y and X and the value range of X. thank you
The shortest side is x, the hypotenuse is 2x, and the other right angle side is root 3 X
Root 3 x * x = y * 2x = 20
Y = root 3 / 2 * x
Root 3 x * x = 20
X = 3.4 (approximately)
Given that the length of the hypotenuse of an isosceles right triangle is x and its area is y, then the functional relationship between Y and X is______ .
As shown in the figure:
∵AC=BC，AC⊥BC，S△ABC=y．AB=x，
∴AC2+BC2=x2，
∴2AC2=x2，
AC2=x2
2，
∵S△ABC=1
2AC•BC=1
2AC2=y，
∴y=1
2×x2
2=x2
4．
So the answer is: y = x2
4．
There is a right triangle with an angle of 60 ° and the functional relationship between its area s and the length of the hypotenuse x is______ .
∵ there is a right triangle with an angle of 60 degrees,
ν let ∠ a = 60 ° then ∠ B = 30 °,
∵ the slope length is X,
∴AC=1
2x，BC=
Three
2x，
The functional relationship between its area s and the length of the hypotenuse x is: S = 1
2×1
2x×
Three
2x=
Three
8x2．
In the RT triangle ABC, if the difference between the two right sides is 2cm, and the hypotenuse C = 10cm, then the height of the hypotenuse is?
Let a right angle side be X. then another right angle side is y (x > y)
x-y=√2
x^2+y^2=10
The solution is: x = 2 √ 2cm, y = √ 2cm
From the equal product formula, we can get the following results
xy=c*h
The solution is: H = 2 √ 10 / 5 (CM)
So the height on the bevel is 2 √ 10 / 5cm
RELATED INFORMATIONS
- 1. In the right triangle ABC, given the right angle side a = root 96, hypotenuse C = root 150, calculate the circumference of the triangle ABC, 18 times 2
- 2. A right triangle. The length of the side opposite the right angle is 10 cm, and the other two sides are 8 cm and 6 cm respectively______ Centimeter
- 3. It is known that the ratio of the hypotenuse of a right triangle to one right angle side is 17:8, and the length of the other right angle side is 60
- 4. It is known that the sides to which △ ABC, ∠ a, ∠ B and ∠ C are respectively a, B, C and a: B: C = 13:12:5, is △ ABC a right triangle? Why? Understanding with Pythagorean
- 5. It is known that the circumference of RT △ ABC is 4 + 2 3, the length of hypotenuse AB is 2 3. Find the area of RT △ ABC
- 6. If the three sides of a right triangle are three consecutive even numbers, and the area is 24, then the three sides of the triangle are respectively pro,
- 7. It is known that: A, B, C are the three sides of the triangle ABC, and the square of a + the square of B + the square of C - 10a-24b-26c = - 338 Proof: this triangle is a right triangle
- 8. In RT △ ABC, ∠ ACB = 90 ° and CD is the height on the edge of AB, ab = 13cm BC = 12cm AC = 5cm 1. Calculate the area of △ ABC 2. The length of CD
- 9. In the RT triangle ABC, the right angle side AB, the oblique side C, and a, B, C form the arithmetic sequence, area = 12, find the perimeter?
- 10. As shown in the figure, in the triangle ABC, BC = 8 cm, ad = 6 cm, e and F are the midpoint of AB and AC respectively______ Square centimeter
- 11. It is known that the sum of the two right sides of a right triangle is 2. Find the minimum length of the hypotenuse and the length of the two right angles when the length of the oblique side reaches the minimum
- 12. Proof: in a right triangle, if a right angle side is equal to half of the hypotenuse, then the acute angle of the right angle is equal to 30 °
- 13. How many isosceles right triangles can be cut from a rectangular paper with a length of 5 decimeters and a width of 2 decimeters? In my son's homework, I divide the area of a rectangle by the area of a triangle to get 125. But the answer is no, it's 120. Obviously, it's wrong to divide the area by the area, I thought for a while, the answer is right, but I don't know how to use the formula. I think that the width of 2 decimeters = 20cm, except the side length of the triangle 4cm can be divided, the width can get the side length of five triangles, but when 50 cm is divided by 4 cm, the length of the rectangle can not be fully used
- 14. The three sides of a right triangle are 12 cm, 16 cm and 20 cm respectively
- 15. If the ratio of the two right sides of a right triangle is 3:4 and the length of the hypotenuse is 25, then the height of the hypotenuse is______ .
- 16. Let a and B be the two right sides of a right triangle. If the circumference of the triangle is 6 and the length of the hypotenuse is 2.5, then the value of AB is () A. 1.5 B. 2 C. 2.5 D. 3
- 17. If the ratio of the two right sides of a right triangle is 3:4 and the length of the hypotenuse is 20, then its area is______ .
- 18. Consult: the oblique side of a right triangle is 15 cm long, and the sum of right angles is 20 cm. Find its area
- 19. One acute angle of a right triangle is 55 ° and the other acute angle is______ °．
- 20. The ratio of one right angle side to the hypotenuse of a right triangle is 12:13, and the length of the other right angle side is 5cm. What is the area of this right triangle?