15. If x^2-3x+2 is a factor of x^4-ax^2+b then find the values of'a' and 'b'.
Answers
Step-by-step explanation:
Given :-
x^2-3x+2 is a factor of x^4-ax^2+b
To find :-
Find the values of 'a' and 'b'.?
Solution :-
Given polynomial = P(x) = x^4-ax^2+b
Given factor of P(x) = x^2-3x+2
=> x^2-x-2x+2
=>x(x-1)-2(x-1)
=> (x-1)(x-2) is a factor of P(x)
We know that
By Factor Theorem,
If x-1 is a factor of P(x) then P(1) = 0
Since x-1 = 0 => x = 1
P(1) = (1)^4 -a(1)^2+b = 0
=> 1 - a(1) +b = 0
=> 1-a+b = 0
=> a = 1+b ------------(1)
If (x-2) is a factor of P(x) then P(2)= 0
Since , x-2 = 0 => x = 2
=> P(2) = (2)^4-a(2)^2+b = 0
=> 16-a(4)+b = 0
=> 16-4a + b = 0
=> 16-4(1+b) +b = 0
=> 16-4-4b +b = 0
=> 12-3b = 0
=> 3b = 12
=> b = 12/3
=> b = 4
Now,
On Substituting the value of b in (1)
=> a = 1+4 = 5
Therefore, a = 5 and b = 4
Answer:-
The values of a and b are 5 and 4 respectively.
Used formulae:-
Factor Theorem:-
Let P(x) be a polynomial of the degree greater than or equal to 1 and x-a is another linear polynomial if x-a is a factor of P(x) then P(a) = 0 vice-versa.
Hello, Buddy!!
✰ Given:-
- x²-3x+2 is a factor of x⁴-ax²+b.
✰ To Find:;
- Value of a & b.
✫ Required Solution:-
⤴️
- Value of a ☞ 5
- Value of b ☞ 4
Hope This Helps!!