TIFR2010-Maths-A-12

Question

The sum of the roots of the equation $x^{5}+3x^{2}+7=0$ is.

• A. $-3$
• B. $\frac{3}{7}$
• C. $\frac{-1}{7}$
• D. $0$

Answer 1

Here in this question sum of roots $=$ coefficient of $x^4$. So, sum $=0$.

In general, sum is $-1 \times$ coefficient of $x^{\text{degree }-1}$ in polynomial.

Answer 2

http://www.mathwarehouse.com/quadratic/roots/formula-sum-product-of-roots.php

simple formula is -b/a= -0/1=0