Increasing and Decreasing Domain of a Parabola: Representation of missing c value

Find the domain of increase of the function:

$y=-8x^2-32x$

x < -2

Find the domain of decrease of the function:

$y=-8x^2-32x$

x > -2

Find the domain of decrease of the function:

$y=4x^2-8x$

x < 1

Find the domain of decrease of the function:

$y=-10x^2-200x$

x > -10

Find the domain of decrease of the function:

$y=-30x^2-60x$

x > -1

Find the domain of decrease of the function:

$y=3x^2+6x$

x < -1

Find the domain of increase of the function:

$y=3x^2+6x$

x > -1

Find the domain of increase of the function:

$y=4x^2-8x$

x > 1

Find the domain of increase of the function:

$y=7x^2-28x$

x > 2

Find the domain of increase of the function:

$y=-x^2+6x$

x < 3

Find the domain of decrease of the function:

$y=-x^2+6x$

x > 3

Find the domain of decrease of the function:

$y=7x^2-28x$

x < 2

Find the domain of increase of the function:

$y=-4x^2+40x$

x < 5

Find the domain of decrease of the function:

$y=-4x^2+40x$

x > 5

Find the domain of decrease of the function:

$y=-3x^2+36x$

x > 6

Find the domain of decrease of the function:

$y=5x^2-40x$

x < 4

Find the domain of increase of the function:

$y=5x^2-40x$

x > 4

Find the domain of increase of the function:

$y=2x^2-24x$

x > 6

Find the domain of increase of the function:

$y=6x^2+24x$

x > -2

Find the domain of increase of the function:

$y=x^2+4x$

x > -2