What does the slope of a quadratic function mean

The slope of a quadratic function at or through a certain point, you should understand after learning the derivative

Tangent slope of quadratic function
Finding the tangent slope of F (x) = 9x ^ 2-12 on (7, f (x))
And the tangent equation

f(x)=9x²-12
f'(x)=18x
f'(7)=126
The tangent slope of F (x) = 9x ^ 2-12 on (7, f (x)) is 126

What's the formula of quadratic function formula method? I forgot? Quick
It's the formula method of solving quadratic function... What 4A only B plus minus root sign

[- B (b ^ 2-4ac)] / 2A

How to find the tangent of quadratic function?
If we know a quadratic function y = x ^ 2-x-6, if the slope of the first function K = 3 and is tangent to the quadratic function, how can we find the analytic expression of the first function?

Take the derivative y '= 2x-1 and y' = 3 to get x = 2. Take 2 into y to get y = - 4. So the tangent point is (2, - 4). The tangent equation is Y - (- 4) = 3 (X-2) y = 3x-10. It should be like this

Quadratic function and tangent problem!
Given a quadratic function, when k is given, find the analytic formula of a function tangent to the quadratic function!
For example: given the quadratic function y = - x2 + X + 3, let the primary function be y = - x + B, k = - 1, and tangent to the quadratic function, find the analytic formula of the primary function!
And find out the tangent point coordinates of the first function and the second function!

Simultaneous y = - x2 + X + 3, y = - x + B
x²－2x－3＋b＝0
They are tangent
The discriminant of the equation △ = 2 & # 178; - 4 (B-3) = 0
∴b＝4
The linear function is y = - x + 4
In this case, the equation x & # 178; - 2x-3 + B = 0, that is, X & # 178; - 2x + 1 = 0
And then we substitute x = 1 for y = - x + 4
∴y＝3
So the tangent point is (1,3)

Tangent of quadratic function
We know the function y = x ^ 2-2x-3. The intersection point with the Y axis is (0. - 3). Find the straight line tangent to the function y = x ^ 2-2x-3. Don't use any slope or derivative, just use junior high school knowledge

I see the later one. It's over point (0, - 3)
Let the analytic expression of the straight line be y = kx-3
Substituting y = kx-3 into y = x ^ 2-2x-3
Then x ^ 2-2x-3 = kx-3
∴x^2-(2+k)x=0
A parabola is tangent to a straight line
∴（2+k）^2-4*1*0=0
∴k=-2
The analytic expression of the straight line is y = - 2x-3

What is slope, function value, intercept

The slope is the tangent (tan) of the angle between the line and the x-axis, and the linear function y = KX + B, K is the slope;
Intercept is the ordinate of the intersection of the line and the coordinate axis, y = KX + B, B is the Y intercept, which is actually the value of y when x = 0;
The value of a function is the value of a function. Usually, in y = KX + B, the value of Y is called the value of a function

Know how to draw the slope and passing point
After (0,2), the slope is 2 and - 2

Let y = KX + B (k is not 0) K be the slope and B be the intercept, then we can get the straight line B by taking the passing point and K into the solution equation

Find the slope and longitudinal intercept of the following lines and draw a graph
（1）x+2y=0 （2）2x+1=0 （3）3x-2y+6=0 （4）y-4=0

1, x + 2Y = 0. Y = - 1 / 2x, slope (- 1 / 2), longitudinal intercept 0
2,2x + 1 = 0, x = - 1 / 2, no slope, no longitudinal intercept
3,3x-2y + 6 = 0, y = 3 / 2x + 3, slope 3 / 2, longitudinal intercept 3
4, y-4 = 0, y = 4, slope 0, longitudinal intercept 4,
Same answer as before

If the image of a function y = KX + 3 passes through point a, the distance from the point to the x-axis is 2, and the distance to the y-axis is 1, try to find the analytic expression of this function

∵ the distance from point a to X axis is 2, the distance from point a to y axis is 1, and the coordinates of point a are (1,2) or (- 1,2) or (- 1, - 2) or (1, - 2). When the coordinates of point a are (1,2), K + 3 = 2, the solution is k = - 1, and the analytic expression of the first-order function is y = - x + 3; when the coordinates of point a are (- 1,2), - K + 3 = 2, the solution is k = 1

What does the slope of a quadratic function mean