A) \[-({{a}^{3}}+3ab)\]
B) \[{{a}^{3}}+3ab\]
C) \[-{{a}^{3}}+3ab\]
D) \[{{a}^{3}}-3ab\]
Correct Answer: C
Solution :
Sum of root \[\alpha +\beta =-a\]and product of roots \[\alpha \beta =b\] So, \[{{\alpha }^{3}}+{{\beta }^{3}}=(\alpha +\beta )({{\alpha }^{2}}-\alpha \beta +{{\beta }^{2}})\] = \[(\alpha +\beta )[{{(\alpha +\beta )}^{2}}-3\alpha \beta ]=-a({{a}^{2}}-3b)=-{{a}^{3}}+3ab\]
You need to login to perform this action.
You will be redirected in
3 sec
