What are sine and cosine functions like? Is the graph axisymmetric and centrosymmetric? Write the axis of symmetry or the point of symmetry
Sine function and y = SiNx symmetry center: [K π, 0] symmetry axis; X = π - 2 + K π cosine function and y = cosx symmetry center [π - 2 + K π, 0] symmetry axis X = k π
Relationship between symmetric axis symmetry center of sine function and cosine function and image key points
For the sine function y = SiNx, the axis of symmetry is x = π / 2 ± K π (k is an integer)
The center of symmetry is x = k π (k is an integer)
For cosine function y = cosx, the axis of symmetry is x = k π (k is an integer)
The center of symmetry is x = π / 2 ± K π (k is an integer)
Keys: Intersections
When x = π / 4 ± K π
Let a be the inclination angle of the straight line y = - root 3x + 2. Then cosa's value is!
According to the title, Tana = 3 and a belongs to (0,90)
So we can get Sina / cosa = 3 and Sina squared + cosa squared = 1
So cosa squared = 1 / 10, because a belongs to (0,90)
So cosa is positive
Through point a (2,1), its inclination angle is half of the inclination angle of the straight line L: 3x4y 5 = 0, and solve the equation of the line
Let the inclination angle of this line be 2n, the new line inclination angle N.2), t denote Tan n.! Tan 2n = 2T / [1-T ^ 2) = - 3 / 4. Cross multiplication, 3T ^ 2-3 = 8t, 3T ^ 2-8t-3 = 0. Cross multiplication, (3T + 1) (T-3) = 0,3t + 1 = 0, t = - 1 / 3
If the inclination angle of the line 3x + 4y-5 = 0 is a, then the inclination angle of the symmetrical line with respect to the line X3 is
Line x = 3 symmetry
Inclination angle = 180 ° - arctan (- 3 / 4)
=arctan(3/4)
If the equation of the second line is 3x-4y = 0, find the equation of the other three lines
The solution of Tan θ = - 3tan3 θ = (Tan θ + tan2 θ) / (1-tan θ, tan2 θ = (Tan θ + tan2 θ) / (1-tan θ tan2 θ) is solved, and the solution of tan3 θ = - 9 / 13tan4 θ = 2tan2 θ / [1 - (tan2 θ) ^ 2] the solution of Tan 4 θ = 3 / 5, so K1 = - 3, K2 = 3 / 4, K3 = - 3 = - 3, K3 = - 3 = - 3, K3 = - 3 = - 3, K3 = - 3 = - 3, K2 = 3 / 4, K3 = - 3 = - 3, K3 = - 3 = - 3, K3 = - 3 = 3, K3 = - 3 = 3, K3 = - 9
Make a straight line L through point a (8,6) and the inclination angle of L is half of the inclination angle of the line 3x-4y-2 = 0
If the inclination angle of the line is a, then tan2a = 3 / 4
The solution is Tana = 1 / 3
The linear equation is y-6 = 1 / 3 (X-8)
It is concluded that x-3y + 10 = 0
The following conditions are solved: passing through the intersection of two lines 2x-3y + 10 = 0 and 3x + 4Y-2 = 0, and perpendicular to the line 3x-2y + 4 = 0; There are two problems in solving the linear equation satisfying the following conditions: (1) Passing through the intersection point of two straight lines 2x-3y + 10 = 0 and 3x + 4Y-2 = 0, and perpendicular to the line 3x-2y + 4 = 0; (2) Through the intersection of two lines 2x + Y-8 = 0 and x-2y + 1 = 0, and parallel to the line 4x-3y-7 = 0
(1) By solving the equations 2x-3y + 10 = 0,3x + 4Y-2 = 0, we can get x = -- 2, y = 2, so the intersection point is (- - 2,2)
(1) The equation of the line parallel to the straight line 3x + 4y-12 = 0 and the distance from it is 7; (2) the equation of the line perpendicular to the line x + 3y-5 = 0 and the distance from point P (- 1,0) is three fifths and root ten
(1) Let the straight line be 3x + 4Y + C = 0. According to the meaning of the title C - (- 12) ︱ / √ (3 ﹢ 4 ﹣ 2) = 7 ︱ C + 12 = 35C + 12 = 35 or C + 12 = - 35C = 23 or - 47, the equation of straight line is 3x + 4Y + 23 = 0 or 3x + 4y-47 = 0 (2) x + 3y-5 = 03y = - x + 5Y = - X / 3 + 5 / 3, and the slope of the line is (- 1) / (-...)
Find the equation of circle C: (x + 2) ^ 2 + (y-6 = 1) on the symmetric circle of the straight line 3x-4y + 5 = 0
The symmetry radius of a circle about a straight line is constant. So, as long as the symmetrical point of the center of the circle is calculated about the line, then C (- 2,6) can be set as C '(a, b), then the vertical straight line CC' 3x-4y + 5 = 0, that is, the midpoint coordinates of the slope multiplied by - 1 cc 'are listed on the line 3x-4y + 5 = 0 according to these two equivalent relations, the equation system can be obtained