A. C.
Use a graphing calculator to sketch the graph of the quadratic equation, and then state the domain and range-
y = -5x² - 4x + 1
D: all real numbers
D: (x20)
R: ( 31.8)
R: all real numbers
b. D: all real numbers
d. D: all real numbers
R: ( 2 1.8)
R: ( 30.2)

Step-by-step explanation:

y = -5x² - 4x + 1 is a quadratic and thus is defined on the domain "all real numbers."  Because of the negative sign in front of the x^2 term, we know that this parabolic curve opens downward.  The x-coordinate of the vertex is x = -b/[2a], which in this case is x = 4/[2*-5], or -4/10, or -2/5.  Using synthetic division to determine the y-coordinate of the vertex, we get vertex (-2/5, 9/5).  9/5 is the maximum y value.  The range is (-infinity, 9/5].

x = ± 6i

step-by-step explanation:

x^2 = -36

take the square root of each side

sqrt(x^2) = sqrt(-36)

we know sqrt(ab) = sqrt(a) sqrt(b)

x = ±sqrt(36) sqrt(-1)

we know that sqrt (-1) = i

x = ± 6i

idk

step-by-step explanation: