Find a cubic function with the given zeros.

-2, 5, -6

f(x) = x3 + 3x2 + 28x - 60

f(x) = x3 - 3x2 - 28x - 60

f(x) = x3 + 3x2 - 28x - 60

f(x) = x3 + 3x2 - 28x + 60

Question

Find a cubic function with the given zeros.

-2, 5, -6

f(x) = x3 + 3x2 + 28x - 60

f(x) = x3 - 3x2 - 28x - 60

f(x) = x3 + 3x2 - 28x - 60

f(x) = x3 + 3x2 - 28x + 60

hartnn · Answer

if 'a' is a zero of f(x), then (x-a)  is one factor
so when '5' is a zero , what is the factor ?

anonymous · Answer

5- a

hartnn · Answer

you put 5 instead of 'x' ?
there 'a' was a zero, here '5' is a zero,
so put a=5 instead

anonymous · Answer

ohhhh okay .

anonymous · Answer

so x - 5

hartnn · Answer

yes, correct :)
what about -2 as a zero ? factor is ?

anonymous · Answer

x + 2

hartnn · Answer

yes!
so i guess you have already figured out that x+6 is also a factor,
so your f(x) = (x+2)(x-5)(x+6)
can you foil ?

anonymous · Answer

mmm , kinda , hang on and i'll try (:

anonymous · Answer

-60 + -28x + 3x2 + x3

hartnn · Answer

thats correct!
good work :D

hartnn · Answer

sorry for late reply, my ninternet is acting weird :P