Chap. 9 - Non linear relations and functions Flashcards
what is the basic form of a parabola?
y=x^2
what is the turning point form of a parabola?
y=a(x-h)^2+k
what is the turning point derived from turning point form?
(h,k) ((x,y) respectively)
what determines concavity and explain how the size of the number affects concavity.
a. if a is larger, the parabola is skinner, but if a is smaller, the parabola gets larger.
when do you sketch via factorising?
when the parabola is in general form
if the parabola is in general form, what key features can be derived without changing the equation?
*concavity (a)
*c is the y intercept
how do you find x intercepts when the parabola is in general form
when y=0
if the parabola is in general form, how do you find the x intercepts?
- make y=0
- factorise and those are the x intercepts
the axis of symmetry is the average of:
the 2 x-intercepts
to convert from general form to turning point form, use:
completing the square
when a parabola is in general form, you can find the x intercepts in 2 ways. they are:
*completing the square, and then using turning point form
*the quadratic formula
the axis of symmetry is equal to:
-b/2a
the axis of symmetry is also:
the x coordinate of the turning point
if you have the aos, you can find the TURNING point by
subbing the x-coordinate into the original equation.
what makes a parabola negative definite?
if the parabola is concave down and always below the x axis.