hi guys anybody has any idea to find the zeroes of cubic polynomial, how to find
Answers
Answer:
Well there aren’t any simple ways but two tricks which I’ve been using:
If a cubic polynomial has a constant,then prime factor of the constant may be one of the plausible solutions.
Eg: x^3+ 3x^2- 6x - 18 = 0;here if you factorise 18,the answer is 2x3x3 ;so it’s plausible that the solutions of the equations may be +2,-2,+3,-3. On actual solving ,we find that the answers are -3, √6 and -√6. So -3 was a possible answer and it is actually one of the answers!
Another method is adding the coefficients. If the sum of all the coefficients is 0(zero),then one of the answers may be 1. If the sum of odd coefficients is 0,then one of the possible answers is -1.
PS:The above tricks may not always hold!
Step-by-step explanation:
use trial and error and factor theorem to check the no. is a factor or not. If it is one divide the cubic polynomial by the factor. U will get a quadratic polynomial factorise it and get all zeros.