One of the two students, while solving a quadratic
equation in x , copied the constant term incorrectly
and got the roots 3 and 2. The other copied the
constant term and coefficient of x2
correctly as −6
and 1 respectively. The correct roots are
Answers
Answer:
here is your answer
correct roots are
x=3 and x= -2
The correct roots of the quadratic equation are 6 and - 1 .
• Let the given quadratic equation be ax² + bx + c = 0.
Here, x represents the roots of the equation.
Coefficient of x² = a
Coefficient of x = b
Constant term = c
• Given,
Incorrect roots of the equation = 3, 2
=> x = 3 ; x = 2.
=> x - 3 = 0 -(i) ; x - 2 = 0 -(ii)
• A quadratic equation is formed by multiplying the linear equations (i) and (ii).
=> (x - 3) (x - 2) = 0 × 0
=> (x - 3) (x - 2) = 0
=> x² - 2x - 3x + 6 = 0
=> x² - 5x + 6 = 0
• Given that the correct value of the coefficient of x² = 1
=> a = 1
Correct value of the constant term = - 6
=> c = - 6
• It is given that the first student copies only the value of the constant term incorrectly.
=> The coefficient of x is copied correctly by the first student.
=> b = - 5
• Now, putting the values of a, b, and c in the quadratic equation correctly, we get,
1.x² + (- 5).x + (- 6) = 0
=> x² - 5x - 6 = 0
=> x² - 6x + x - 6 = 0
=> x (x - 6) + 1 (x - 6) = 0
=> (x - 6) (x + 1) = 0
=> x - 6 = 0 ; x + 1 = 0
=> x = 6 ; x = - 1
• Therefore, the correct roots of the given quadratic equation are 6 and - 1 .