friends please help me
and please don't post irretative answers..
Answers
Answer:
Option c
Step-by-step explanation:
Given :-
α and β are the roots of the equation is (a+1)x²+(2a+3)x+(3a+4) = 0 and αβ = 2
To find :-
Find the value of α+β ?
Solution :-
Given equation is
(a+1)x²+(2a+3)x+(3a+4) = 0
On comparing with the standard quadratic equation ax²+bx+c = 0 then
a = (a+1)
b = (2a+3)
c = (3a+4)
Given roots are α and β then
We know that
Sum of the roots = -b/a
=> α+β = -(2a+3)/(a+1) ----------(1)
and
Product of the roots = c/a
=>αβ = (3a+4)/(a+1) -------------(2)
According to the given problem
αβ = 2 -------------------------------(3)
Now,(2) becomes
=> (3a+4)/(a+1) = 2
=> 3a+4 = 2(a+1)
=> 3a+4 = 2a+2
=> 3a-2a = 2-4
=> a = -2
On substituting the value of a in (1) then
=> α+β = -[2(-2)+3]/[-2+1]
=> α+β = -(-4+3)/(-1)
=> α+β = -(-1)/-1
=> α+β =1/-1
=> α+β = -1
Therefore, α+β = -1
Answer:-
The value of α+β for the given problem is -1
Check:-
If a = -2 then given equation becomes
(-2+1)x²+(2×-2+3)x+(3×-2+4) = 0
=> (-1)x²+(-4+3)x+(-6+4) = 0
=> -x²-x-2 = 0
=> x²+x+2 = 0
On comparing with the standard quadratic equation ax²+bx+c = 0 then
a = 1, b = 1, c = 2
Sum of the zeroes = -b/a
=> -1/1
=> -1
Product of the zeroes = c/a
=> 2/1
=> 2
We have, α+β = -1 and αβ = 2
Verified the given relations in the given problem
Used formulae:-
- The standard quadratic equation is ax²+bx+c = 0
- Sum of the roots = -b/a
- Product of the roots = c/a