Obtain all other zeros of 3x⁴+ 6x³- 2x²- 10x- 5, if two of its zeros are√5/3 and -√5/3
Answers
♠ Obtain all other zeros of 3x⁴+ 6x³- 2x²- 10x- 5, if two of its zeros are√5/3 and -√5/3 .
✒ The zeroes of the given polynomial are -√(5/3), √(5/3) , -1, -1 .
Given p(x) = 3x⁴+6x³-2x²-10x-5--(1)
The degree of p(x) is 4 , so it has
atmost 4 zeroes.
The two zeroes of given p(x) are
√(5/3) and -√(5/3)
The equation of the polynomial
whose zeroes are √(5/3) and -√(5/3 )
= ( x+√5/3 )( x - √5/3 )
= x² - 5/3 --- (2)
Divide (1) with ( 2 ) , we get
x²-5/3)3x⁴+6x³-2x²-10x-5(3x²+6x+3
********3x⁴+ 0 - 5x²
___________________
*************6x³+3x²-10x-5
*************6x³ + 0 - 10x
___________________
******************3x² + 0 - 5
******************3x² + 0 - 5
____________________
******************* ( 0 )
p(x) = ( x²-5/3)( 3x²+6x+3 )
= 3(x²-5/3)( x²+2x+1 )
= 3[ x² - {√(5/3)}² ] ( x + 1 )²
= 3(x+√5/3)(x-√5/3)(x+1)(x+1)
Therefore , The zeroes of the given polynomial are -√(5/3), √(5/3) , -1, -1 .
____________________________________
Answer: