19. Find the quadratic polynomial whose zeroes are in the ratio 2:3 and their sum is 15.
Answers
Answer:
x²-15x+6
Step-by-step explanation:
given:- sum of zeroes = 15
-b/a = 15
than, b = -15 and a = 1
and ratio of zeroes =2:3
product of zeroes = c/a
6 = c/a
then, c = 6 and a = 1
hence, the quadratic polynomial will be
x²-15x+6...
Given:-
- Ratio of the zeroes of the quadratic polynomial = 2:3
- Sum of the zeroes = 15
To Find:-
- The quadratic polynomial
Assumption:-
- Let the ratio constant be x
- 1st zero = 2x
- 2nd zero = 3x
Solution:-
As it is given that the sum of the zeroes is 15
Hence,
2x + 3x = 15
=> 5x = 15
=> x = 15/5
=> x = 3
Now,
1st zero = 2x = 2 × 3 = 6
2nd zero = 3x = 3 × 3 = 9
Now,
As the sum of the zeroes is already given,
Let us find out the product of the zeroes.
This
Product of the zeroes = 6 × 9 = 54
So we have
- Sum of zeroes = 15
- Product of zeroes = 54
Wee know,
A quadratic equation is always in the form:-
x² - (sum of the zeroes)x + product of zeroes
Hence,
Putting the values:-
x² - (15)x + 54
=> x² - 15x + 54
Hence, the required quadratic equation is x² - 15x + 54.
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Verification!!!
Let us verify whether the equation we got is correct or not.
We know,
Sum of zeroes = -(Coefficient of x)/(Coefficient of x²)
Hence,
= 15 = -(-15)/1
=> 15 = 15
Also,
Product of zeroes = (Constant Term)/Coefficient of x²)
= 54 = 54/1
=> 54 = 54
Hence, Verified!!!
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