Question

If a - b, a and a + b are zeroes of the polynomial x² – 3x² + x + 1 the value of (a + b) is_________
(a) 12 (b) -1+2
(C) -1-2
(d) 3​

Answer 1

SO, UR QUES.. IS

If the zeroes of polynomial x³-3x²+x+1 are (a-b),a, (a+b), find a and b.

→ a = 1  and b = ±√2 .

Step-by-step explanation:

Given polynomial is f(x) = x³ - 3x² + x + 1 .

Here  a = 1 , b = -3 , c = 1 , d = 1 .

Let α = ( a - b ) , β = a and γ = ( a + b ) .

As we know,

→ α + β + γ = -b/a .

⇒ ( a - b ) + a + ( a - b ) = -(-3)/1 .

⇒ 3a = 3 .

⇒ a = 3/3 .

∴ a = 1 .

And,

→ αβ + βγ + γα = c/a .

⇒ a( a - b ) + a( a + b ) + ( a + b )( a - b ) = 1/1 .

⇒ a² - ab + a² + ab + a² - b² = 1 .

⇒ 3a² - b² = 1 .

⇒ ( 3 × 1² ) - b² = 1 .         { ∵ a = 1 }

⇒ 3 - b² = 1 .

⇒ b² = 3 - 1 .

⇒ b² = 2 .

∴ b = ±√2 .

Hence, it is solved .

Step-by-step explanation: