if alpha and beta are root of the equation x^2-2x+3=0 then the equation whose roots are alpha+2 and beta +2
Answers
Answer:
Step-by-step explanation:
Let α, β be the roots of the equation
x² - 2x + 3 = 0,
Let f(x) = x² - 2x + 3
Given that roots are increased by 2, so new roots
of the equation are α + 2, β + 2
Let y = α + 2 which is the required root of new
equation,
So, α = y - 2
But, we know α is root of f(x), hence
f(α) = 0
But α = y - 2, so
f(y - 2) = 0
(y - 2)² - 2(y - 2) + 3 = 0
y² - 6y + 11 = 0,
Given Equation:
Sum of roots = α + β = -b/a = -(-2)/1 = 2
⇒ Sum of roots of new equation = α + 2 + β + 2
⇒ Sum of roots of new equation = α + β + 4
⇒ Sum of roots of new equation = 2 + 4 = 6
Similarly, Product of roots = c/a = αβ = 3/1 = 3
Product of roots of new equation = ( α + 2 ) ( β + 2 )
⇒ Product of roots of new equation = αβ + 2α + 2β + 4
⇒ Product of roots of new equation = αβ + 2 ( α + β ) + 4
⇒ Product of roots of new equation = 3 + 2 ( 2 ) + 4
⇒ Product of roots of new equation = 3 + 4 + 4 = 11
Therefore new equation is given as:
⇒ x² - ( Sum of roots ) x + Product of roots