Question

If one zero of the polynomial 2x square + bx + 4 is equal to zero is 2 find the other zeros also find the value of p

Answer 1

as 2 is one zero of the polynomial

$2 {x}^{2} + bx + 4 = 0$

hence it must satisfy this equation

therefore,

$2 {(2)}^{2} + b(2) + 4 = 0 \\ 2b + 8 + 4 = 0 \\ 2b = - 12 \\ b = - 6$

so now lets do factorisation

$2 {x}^{2} - 6x + 4 = 0 \\ 2 {x}^{2} - 4x - 2x + 4 = 0 \\ 2x(x - 2) - 2(x - 2) = 0 \\ (x - 2)(2x - 2) = 0 \\ or \: \: \: (x - 2)(x - 1) = 0$

therfore, x=1 is another root