Question

If a and b are the zeros of f(x)= x²- x -4, find the value of 1\alpha + 1\beta - alpha beta

Answer 1

1/alpha+1/beta-alpha.beta
Can be written as
(Alpha + beta/alpha.beta)-alpha beta
Alpha +beta=-b/a Alpha.Beta=c/a
So it can be written as
(1/-4)-(-4)
-1/4+4=15/16