Question
The interval in which the function f(x)= 4 x^2+1 x is decreasing is :
BITSAT
Mathematics
Application of Derivatives
2023
BITSAT 2023 (Memory Based Paper 1)
BITSAT Mathematics Question (2023) — Solution
Options
- A. (- 1 2 , 1 2 )
- B. [- 1 2 , 1 2 ]
- C. (-1,1)
- D. [-1,1]
Answer
A. (- 1 2 , 1 2 )
Step-by-step solution
Given f(x)= 4 x^2+1 x Thus f^ (x)=4- 1 x^2 f ( x ) will be decreasing if f ^ ( x ) Thus 4- 1 x^2 4 -1 2 Thus interval in which f(x) is decreasing, is (- 1 2 , 1 2 ).
Related: Mathematics — Application of Derivatives · All PYQ Banks