Number of solutions of 3 2 + 8 + 3 3 = 0, [-3 , 2 ] is :
- 5
- 4
- 3
- 0
Answer
(1) 5
Solution
3 (2 2 - 1 ) + 8 + 3 3 = 0
2 3 2 + 8 + 2 3 = 0
3 2 + 4 + 3 = 0
( 3 + 1 ) ( + 3 ) = 0
- 3 = - 1 3
Let = -1 (- 1 3 ) ( 2, ); general solution = 2k
In [-3 , 2 ]: = , - , 2 - , -2 + , -2 -
(-2 - > -3 as < ; -4 + < -3 and 2 + > 2 are rejected)
number of solutions = 5
Answer: (1)