First, the conic curve equation

1, ellipse:+=1(a > b > 0) or+=1(a > b > 0) (where a2=b2+c2).

2. hyperbola:-=1(a >; 0, b>0) or -= 1 (a > 0, b>0) (where c2=a2+b2).

3. Parabola: y2 = 2px (P&G T; 0)，x2 = 2py(p & gt； 0)。

Second, functional parity.

1. If any x in the function definition domain has f(-x)=-f(x), the function f(x) is called odd function.

2. If any x in the function definition domain has f(x)=f(-x), the function f(x) is called an even function.

Thirdly, the method of finding function value domain.

1. direct method: from the range of independent variable x, the range of y=f(x) is derived, which is suitable for simple compound functions.

2. method of substitution: method of substitution transforms a function into the evaluation domain of a quadratic function, which is applicable to both the inside and outside of the root form.

Fourth, the zero point of quadratic function

1, △ > 0, the equation has two unequal real roots, the image of the quadratic function has two intersections with the axis, and the quadratic function has two zeros.

2.△ = 0, the equation has two equal real roots (multiple roots), the image of the quadratic function intersects with the axis, and the quadratic function has a double zero or a second-order zero.

3.△ < 0, the equation has no real root, the image of the quadratic function has no intersection with the axis, and the quadratic function has no zero point.

Fifth, find the main basis of function definition domain.

1, the denominator of the fraction is not zero.

2. The number of even roots is not less than zero, so it is meaningless to take the zeroth power of zero.

3. The real number of logarithmic function must be greater than zero.