Obtain all the zeroes of the polynomial X^4 - 3√2 x³ + 3x² +3 √2x - 4 = 0 , if two of it's zeroes are √2 and 2√2 ... Guys , Solve out !!!
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P(x) = x⁴ - 3 √2 x³ + 3 x² + 3√2 x - 4
given that (x - √2) , (x - 2√2) are factors of P(x) as √2 and 2√2 are two zeroes of P(x) = 0.
(x -√2) (x - 2√2) = x² -3√2 x + 4 is a factor of P(x). let A be a constant. We can write the constant term in the second factor by : -4/4 = -1... dividing the constant terms.
let (x² - 3√2 x + 4) (x² + A x -1 ) = P(x)
Now compare the coefficients of x³ : A - 3√2 = -3√2 => A = 0
coefficient of x : 4A + 3√2 = 3√2 => A = 0
so the other factors are : x² - 1 = 0
so x = 1 and -1 are the other factors.
This method of multiplying the factors and comparing coefficients is simple.
given that (x - √2) , (x - 2√2) are factors of P(x) as √2 and 2√2 are two zeroes of P(x) = 0.
(x -√2) (x - 2√2) = x² -3√2 x + 4 is a factor of P(x). let A be a constant. We can write the constant term in the second factor by : -4/4 = -1... dividing the constant terms.
let (x² - 3√2 x + 4) (x² + A x -1 ) = P(x)
Now compare the coefficients of x³ : A - 3√2 = -3√2 => A = 0
coefficient of x : 4A + 3√2 = 3√2 => A = 0
so the other factors are : x² - 1 = 0
so x = 1 and -1 are the other factors.
This method of multiplying the factors and comparing coefficients is simple.
Hence the polynomial is simple : x² - (0) x + (-1)
roots of this are +1 and -1.
Answered by
38
Answer:P(x) = x⁴ - 3 √2 x³ + 3 x² + 3√2 x - 4
given that (x - √2) , (x - 2√2) are factors of P(x) as √2 and 2√2 are two zeroes of P(x) = 0.
(x -√2) (x - 2√2) = x² -3√2 x + 4 is a factor of P(x). let A be a constant. We can write the constant term in the second factor by : -4/4 = -1... dividing the constant terms.
let (x² - 3√2 x + 4) (x² + A x -1 ) = P(x)
Now compare the coefficients of x³ : A - 3√2 = -3√2 => A = 0
coefficient of x : 4A + 3√2 = 3√2 => A = 0
so the other factors are : x² - 1 = 0
so x = 1 and -1 are the other factors.
This method of multiplying the factors and comparing coefficients is simple.
Step-by-step explanation:
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