# If #a# and #k# are real, for what values of #k# does #z^3 +az^2 + kz + ka = 0# have: a) one real root b) 3 real roots?

##### 1 Answer

Apr 4, 2017

#### Answer:

See below.

#### Explanation:

so as we can observe,

always has a real root which is

and if