Other two zeroes of x⁴ – 3x³ + 6x – 4, if two of its zeroes are √2 and -√2
Answers
Given:
- A polynomial x⁴-3x³+6x-4 with zeroes √2 and -√2
To Find:
- Other zeroes of given polynomial
Solution:
Let given polynomial be p(x)= x⁴-3x³+6x-4
It is given that √2 and -√2 are the zeroes of given polynomial, then
(x-√2) and (x+√2) will be the factors of p(x)
Also,
(x-√2)(x+√2)= x²-2 will be the the factor of p(x)
Now, on dividing p(x) by x²-2, we will get the other factor
(Calculation in the attachment)
So, x²-3x+2 is the other factor of p(x)
Now,
x²-3x+2
= x²-2x-x+2
= x(x-2)-1(x-2)
= (x-1)(x-2)
So, (x-1) and (x-2) are the factors of p(x)
Therefore, 1 and 2 are the other two zeroes of the p(x)
Given, √2 , -√2 are zeroes of polynomial
Px=X⁴+3x³+6x-4
therefore,(x-√2)(x+√2)=x²-2
now dividing the given polynomial by x²-2
Find=the other zeroes of polynomial
here refer the attachment ,
•°•X⁴-3X³+6X-4=(X²-2)(X²-3X+2)
(X²-2)(X²-2X-X-2)
(X²-2)(X-2)(X-1)
•°•(x-2)(X-1) are two factor
hence,
x-2=0
X=2
x-1=0
X=1
Therefore, the other 2 zeroes of polynomial are 2,1