Math with Dhruv
Introduction to Quadratic realaions
Quadratic formulas are used to calculate the height of falling rocks, kicked balls or an arched bridge. The formula is always y=ax^2+bx+c with a = 0. b and c can be 0.
y=3x^2 is an example of b and c as 0. y=2x^2+4x+4 is an example of y=ax^2+bx+c.
Non examples are: y = 5x^3– 5x^2 (2 is not the highest exponent)
y = 3x + 7^2 (can be simplified to 3x + 49, which is linear)
First and Second differences
You will use First and Second difference to determine weather the relation is linear, quadratic or neither. You will take the first number and subtract it by the second number. That will give you one first difference. Then you will take the second number and subtract it by the third number. That will give you another first difference. Keep doing that until all the numbers finish. Then if the first differences are constant the relation is linear. If the first differences are non constant do the same thing with them. And determine the second differences. If the second differences are constant, the relation is quadratic. If both the first and second differences are non constant, then the relation is neither.
characteristics of Parabola
Transformations of Parabola
when you take a Parabola and move it, it is called Transformations of Parabola. You can move the Parabola vertically or horizontally. Suppose your parabola is y=x^2-2 and you want to make it y=x^2+5. This is moving it vertically up 5 units. If you have an equation like y=(x+2)^2 and it is moved to y=(x-1)^2, it is moved 3 units to the left. If you want to move horizontally negative units then the Parabola will shift to the left, and it will shit to the right if you move positive units horizontally.
Writing equations from given transformations
Determine the equation from given vertex and a point
suppose you have the vertex, (1,3) and the point (4,8). I will show you how to determine the equation from the given information. Parabola of standard form y=a(x-h)^2+k. The vertex is (1,3) which is (h,k) and the giving point (4,8) which is (x,y). Now lets sub in the numbers. 8=a(4-1)^2+3