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On the right side of the axis of symmetry of the parabola y = 2x ^ 2-8x + 7, there is a point a moving on the parabola Make a parabola crossing ab ‖ X axis through point a at another point B. there is a point m (2, a) on the symmetry axis (1) If the vertex of the parabola is C, write the coordinates of C (2) If a = 3, when point a moves to where, is the quadrilateral acbm a diamond? (3) Can the quadrilateral acbm be a square? If so, find out the coordinates of point m; if not, explain the reason The key lies in the third question, finding a = 0, which involves the formula of coordinates of two points on the number axis. Can junior high school students accept it.
1. Axis of symmetry x = 2
y=8-16+7=-1
Coordinates of C (2, - 1)
2. If the quadrilateral acbm is a diamond, the ordinate of the center of the diamond is 1
1=2x^2-8x+7
x^2-4x+3=0
X = 1 (on the left side of the axis of symmetry) x = 3
When point a moves to (3,1), the quadrilateral acbm is a diamond
3. It's a square, angle ACM = 45
The equation of AC
y=x-3=2X^2-8X+7
X = 2 (point C) x = 5 / 2
y=-1/2
Coordinates of point m (2,0)
Vt image and XT image in Physics
What does the intersection of two lines in VT image mean? What does the intersection of two lines in XT image mean·
The intersection of two lines in VT image means that at the time corresponding to the intersection, the speed of two objects is equal and the distance reaches the maximum or minimum, while the intersection of two lines in XT image means that the distance of two objects is equal
Why do physical XT and VT images only represent linear motion?
Because x = vt
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