Determine the range of the function.
y = -2x2 + 3
A)
all real numbers
B)
all integers greater than or equal to 3
C)
all real numbers less than or equal to 3
D)
all real numbers greater than or equal to 3

Question

Determine the range of the function. 
y = -2x2 + 3
A)
all real numbers
B)
all integers greater than or equal to 3
C)
all real numbers less than or equal to 3
D)
all real numbers greater than or equal to 3

shadowfiend · Answer

Remember, range is the set of y values that the function can produce. Since x is squared, that means $x^2$ will never be negative, it will be a minimum of zero. But, there's a negative out front, which flips the parabola that is described, so the *maximum* of $-2x^2$ will be 0. Is that enough for you to figure out the range?