MULTIPLE CHOICE QUESTIONS (INCREASING & DECREASING)

1) The interval on which the function f(x)= 2x³+ 9x²+ 12x -1 is decreasing is

a) [1, ∞) b) ( -∞, -2] c) [-2,-1] d) [-1, 1]

2) The interval in which the function f(x)= 2x³+ 3x²- 12x +1 is strictly increasing is

a) [-2,1] 

b) ( -∞, -2] U [1,∞)

c) ( -∞, 1]

d) ( -∞, -1] U [2, -∞)

3) The function f(x)= x² e⁻ˣ strictly increases on

a) [0,2]  b) [0, ∞) c) ( -∞, 0] U [2, ∞) d) none

4) The function f(x)= x⁴ - 4x is strictly 

a) decreasing in [1,∞)

b) increasing in [1,∞)

c) increasing in (-∞, 1]

d) increasing in [-1,1]

5) The function f(x)= x²- 2x is strictly decreasing in the interval 

a) (-∞,1] b) [1, ∞) c) [-1, ∞) d) none

6) The function f(x)= x(x -3)² decreases for the values of x given by 

a) 1≤x ≤3 b) x≤0 c) x≥ 0 d) 0≤ x ≤ 3/2

7) The function f(x)= xˣ, x> 0, is increasing on the interval 

a) (,e] b) (0, 1/e) c) [1/e, ∞) d) none

8) The function f(x)= aˣ is increasing on R if 

a) a>0 b) a<0 c) 0<a<1 d) a > 1

8) P(x)= - 5x²+ 125x + 37500 is total profit function of a company where x is the production of the company.

Find the interval in which the profit is strictly increasing.

9) The shape of a toy is given as f(x)= 6(2x⁴ - x²). To make the toy beautiful 2 sticks which are perpendicular to each other were placed at a point (2,3), above the toy. 

Based on the above information, Find the interval where f(x) is increasing?