Find a degree 3 polynomial having zeros -8, 3 and 7 and the coefficient of x^3 equal 1?

Question

how do you start the steps

4491 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-05-04T16:42:18

Polynomial is #x^3-2x^2-59x+168#

A degree #3# polynomial having zeros #alpha,beta# and #gamma# and the coefficient of #x^3# equal #a# is

#a(x-alpha)(x-beta)(x-gamma)#

Hence the desired polynomial is

#1(x-(-8))(x-3)(x-7)#

= #(x+8)(x-3)(x-7)#

= #(x+8)(x^2-10x+21)#

= #x^3-10x^2+21x+8x^2-80x+168#

= #x^3-2x^2-59x+168#