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9. Find the values of p and q so that the polynomialx^3+ px^2- 37x +q is exactly divisible by x^2 -3x+2 |
Answer» Given :-Cubic polynomial : x³ + px² - 37x + q The given cubic polynomial is exactly divisible by x² - 3x + 2 Required to FIND :-
Solution :-Given information :- Cubic polynomial : x³ + px² - 37x + q The given cubic polynomial is exactly divisible by x² - 3x + 2 we need to find the values of p and q . Let's consider the given polynomial as ; p ( x ) = x³ + px² - 37x + q Now, Let's Factorise x² - 3x + 2 ➜ x² - 3x + 2 ➜ x² - 2x - 1x + 2 ➜ x ( x - 2 ) - 1 ( x - 2 ) ➜ ( x - 2 ) ( x - 1 ) From this we can conclude that ; p ( x ) is exactly divisible by ( x - 2 ) & ( x - 1 ) So, Let ; => x - 1 = 0 => x = 1 p ( 1 ) = ( 1 )³ + p ( 1 )² - 37 ( 1 ) + q = 0 1 + p ( 1 ) - 37 + q = 0 1 + p - 37 + q = 0 - 36 + p + q = 0 q = - p + 36 ➜ equation - 1 consider this as equation 1 Similarly, Let ; => x - 2 = 0 => x = 2 p ( 2 ) = ( 2 )³ + p ( 2 )² - 37 ( 2 ) + q = 0 8 + p ( 4 ) - 74 + q = 0 8 + 4P - 74 + q = 0 - 66 + 4p + q = 0 Substitute the value of q from equation 1 - 66 + 4p + ( - p + 36 ) = 0 - 66 + 4p - p + 36 = 0 3p - 30 = 0 3p = 30 p = 30/3 p = 10 Substitute the value of p in equation 1 q = - p + 36 q = - ( 10 ) + 36 q = - 10 + 36 q = 26 |
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