Question

If one zero of the polynomial 2xsquare+px+4 is 2, find the other zero and also find the value of p

Answer 1

let f(x) = 2x^2 + px + 4 . since 2 is one of it,s zeroes so f(2) must be equal to zero. So,
                          2 x 2^2 + 2p + 4 = 0
                      or,12 + 2p = 0
                      or, 2p = - 12
                      or ,p = -6

therefore the polynomial is 2x^2 - 6x + 4
let the other zero be x
                      so x + 2 = 3 ( since sum of the zeroes of a polynomial    ax^2 + bx + c = 0 is -b/a)
                       thus x=1
                 so the other zero is (x-1)