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Polynomials

Question
CBSEENMA10006099

Find the zeroes of the following quadratic polynomials and verify the relationship between the zeroes and the coefficients.
          3 straight x squared minus straight x minus 4.
               


      
     

Solution
We have,
3a2 – x – 4 = 3x2 – 4x + 3x – 4
= x(3x – 4) + 1(3x – 4)
= (x+ 1) (3x – 4)
So, the value of 3x2 – a – 4 is zero, when (a + 1) = 0 or (3x – 4) = 0
i.e.,      straight x equals negative 1   or    straight x equals 4 over 3
Now, 
     Sum of zeroes = negative 1 plus 4 over 3 equals fraction numerator negative 3 plus 4 over denominator 3 end fraction equals 1 third
                             = fraction numerator negative left parenthesis Coefficient space of space straight x right parenthesis over denominator Coefficient space of space straight x squared end fraction
Product of zeroes = negative 1 cross times 4 over 3 equals negative 4 over 3
                            space space equals space fraction numerator Constant space term over denominator Coefficient space of space straight x squared end fraction.