Question

If one zero of the following polynomial 8x^2-13x-4k is the reciprocal of the other, then find k

Answer 1

Explanation:

hello :

if x1 and x2 this zero for ax²+bx+c you have : x1 = 1 /x2 means :x1 × x2 =1

but : x1 × x2 = c /a

in this exercice : a =8 and b = -13 and c = - 4k

so : c/a =-4k/8

so : -4k/8 = 1

-4k = 8 k = 8/-4 k = -2

this polynomial is : 8x²-13x +8