Image and Attribute Formula: Quadratic Function
parabola
Image symmetry is the key; Openings, vertices and intersections that determine the appearance of the image; The opening and size are broken by A, C intersects the Y axis, and the symbol of B is special, and the symbol is associated with A; First find the vertex position and take the y axis as.
reference line
0 is around, remember that there is no doubt in your heart;
Vertex coordinates
The most important thing is that the general formula is now available, and the horizontal line label is
axis of symmetry
, vertical scale
Function maximum value
See if you have found the position of the symmetry axis. The symbols are reversed and different expressions can be interchanged.
The proof song of the circle: it is not difficult to prove the circle, and the radius and diameter are often connected; Chords can be used as the center distance of chords to vertically divide chords; The diameter is the largest chord of a circle, straight.
circumferential angle
Standing at the top, if it bisects the chord vertically, the vertical diameter,
outstanding
Knock on your ears; There are also angles related to the circle, don't forget that they are interrelated, such as the circumference, the center of the circle,
Angle of chord
Carefully find relationships and connect. The angles of the circles of the same arc are equal, so it is most commonly used to prove the problem. If there is a tangent angle in the circle, it is easy to find the arc. Yuan You
Inscribed quadrilateral
Diagonal complementarity Keep in mind that the outer angle is equal to the inner diagonal, and the quadrilateral is inscribed with a circle; Right angle opposite or * * * chord, try to add auxiliary circle; If the problem is reversed,
Four dots * * * circle
Can solve problems; In order to prove that the tangent of the circle, the vertical radius passes through the outer end, and the straight line and the circle have * * * points, it is necessary to prove that the vertical radius is connected and the straight line and the circle are not given points.
work
vertical line
; Quadrilateral existence
inscribed circle
, is the condition of edge and equality; If you meet a circle, it is important to know the location. The tangency of two circles is a common tangent, and the intersection of two circles is a common chord.
Proportional line segment in the circle: in the case of equal product, change the equal ratio and find similarity vertically and horizontally; Don't be angry, switch to equal lines and ratios, encounter equal ratios, change equal products, quote projective and circular powers, parallel lines, turn proportions, and find the connection between the two ends.