1, parabola is an axisymmetric figure. The symmetry axis is a straight line x =-b/2a. The intersection of symmetry axis and parabola is the vertex p of parabola. Especially when b=0, the symmetry axis of the parabola is the Y axis (that is, the straight line x=0).

2. Both the linear coefficient b and the quadratic coefficient a*** determine the position of the symmetry axis. When A and B have the same number (ab>0), the symmetry axis is on the left side of Y axis; When a and b have different numbers (i.e. AB

3. The general form of logarithmic function is that it is actually the inverse of exponential function. Therefore, the stipulation of a in exponential function is also applicable to logarithmic function.

4. The meaning of zero point of function: the zero point of function is the real root of equation, that is, the abscissa of the intersection of image and axis of function. That is, the equation has a real number root, the image of the function has an intersection with the coordinate axis, and the function has a zero point. 5. Definition of pyramid: One face is a polygon and the other faces are triangles with a common vertex. The geometry surrounded by these faces is called a pyramid.