Question

In which interval does f(x) = -2x^2 - 3x - 4 have a maximum value?

Answer 1

help me

Answer 2

its max is at x = -3/4

Answer 3

It is a quadratic with a negative parabolic curve which continues to infinity in both directions. Do you mean what is the maximum value of the range?

Answer 4

yes

Answer 5

its result is (-1, 0) but i don't know why?

Answer 6

ok...
Differentiate the function giving -4x -3 [for maxima or minima, in this case maxima]

so x = -3/4

Answer 7

but how we know max = (-1 , 0)?

Answer 8

because that is a range of possible x's from -1 to 0. The value for x = -3/4 lies in that range

Answer 9

basically, x = -3/4 is between -1 and 0

Answer 10

ohhh ok Thanks