Mathematics : Application of Derivatives

Find the intervals in which the following functions are strictly increasing or strictly decreasing:
2x³ – 8x² + 10x + 5

Find the intervals in which the following functions are strictly increasing or strictly decreasing:
2x³ – 6x² – 48x + 17

Find the intervals in which the following functions are strictly increasing or strictly decreasing:
f (x) = 2x³ – 9x² + 12x + 30

Find the intervals in which the following functions are strictly increasing or strictly decreasing:
f (x) = 2x³ – 3x² – 36x + 7

Find the intervals in which the following functions are strictly increasing or strictly decreasing:
f(x) = 2x³ – 21x² + 36x – 40 

Find the intervals in which the following functions are strictly increasing or strictly decreasing:
4x³ – 6x² – 72x + 30

Find the intervals in which the following functions are strictly increasing or strictly decreasing:
– 2x³ – 9x² – 12x + 1

Find the intervals in which the function
, is
(a) increasing (b) decreasing.

Find the intervals in which the function f is given by 

(i) increasing    (ii) decreasing

Determine for which values of x, the function f (x) = x⁴ – 2x² is increasing or decreasing.