Question
If be a root of the equation 4 x^2+2 x-1=0, then the other root of the equation is
BITSAT
Mathematics
Quadratic Equation
2022
BITSAT 2022
BITSAT Mathematics Question (2022) — Solution
Options
- A. 4 ^3+2
- B. 4 ^2-2
- C. 4 ^3-3
- D. 4 ^3+3
Answer
C. 4 ^3-3
Step-by-step solution
4 x^2+2 x-1=0 + =- 1 2 , =- 1 4 Also, 4 ^2+2 -1=0 as is a root and we have to prove that =4 ^3-3 . Now, 4 ^3-3 =4 ^2 -3 = (1-2 )-3 =-2 ^2-2 =- 1 2 [4 ^2+4 ]=- 1 2 [1-2 +4 ] =- 1 2 (1+2 )=- 1 2 - = Now, + =- 1 2 [from Eq. (i)] Hence, =4 ^3-3 .
Related: Mathematics — Quadratic Equation · All PYQ Banks