Find the interval in which the following function f(x) = `x^3 + 2x^2 -1` is strictly decreasing.

Determine the intervals in which the following functions f (x) = x^2 + 2x - 5 are strictly increasing or strictly decreasing.

Find the intervals in which the function : f(x) = x^3 + 3x^2 - 105 x + 25 is strictly decreasing

Find the intervals in which the function : f(x) = 2 x^3 - 3 x^2 - 36x + 7 is Strictly decreasing

Find the intervals in which the function f(x) = 17 - 18x + 12x^2 - 2x^3 is strictly decreasing,

Find the intervals in which the function: f(x) = 3x^4 - 4x^3 - 12x^2+5 is strictly decreasing.

Find the intervals in which the functions: f(x) =x^3 + 2x^2 - 1 is strictly increasing and decreasing

Find the intervals in which the function : f (x) = 20 - 9x + 6x^2 - x^3 is strictly decreasing.

Find the intervals in which the function f(x) = 30 - 24 x + 1 5x^2- 2x^3 is strictly decreasing.