| 1. |
A and b are the zeros of 4x^2-5x-1,then a^2b-b^2a= |
|
Answer» Answer: - √41 / 16 Step-by-step EXPLANATION: Given-----> a and b are zeroes of ( 4x² - 5x - 1 ) To find -----> Value of ( a²b - b²a ) Solution-----> ATQ, 4x² - 5x - 1 has zeroes as a and b , We know that, Sum of zeroes = - Coefficient of x / Coefficient of x² => a + b = - ( - 5 ) / 4 => a + b = 5 / 4 Product of zeroes = Constant term / Coefficient of x² AB = - 1 / 4 Now, a²b - b²a = ab ( a - b ) = ab √( a - b )² We know that, ( a - b )² = ( a + b )² - 4ab , putting it , we get a²b - b²a = ab √{ ( a + b )² - 4ab } = ( -1/4 ) √{ ( 5/4 )² - 4 ( -1/4 ) } = ( -1/4 ) √{ ( 25/16) + 1 } = ( -1/4 ) √{ ( 25 + 16) / 16 } = ( -1/4 ) √( 41/16) = ( -1/4 ) √41/ 4 = - √41 /16 |
|