If roots of equation $2 x ^ { 4 } - 3 x ^ { 3 } + 2 x ^ { 2 } - 7 x - 1 = 0$ are $\alpha , \beta , \gamma \text { and } \delta$ then value of $\displaystyle \sum \dfrac { \alpha + 1 } { \alpha }$ is equal to ?
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-3
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3
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$\frac { 11 } { 2 }$
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-11
A
Correct answer
Explanation
For the equation 2x^4 - 3x^3 + 2x^2 - 7x - 1 = 0, the sum of (alpha + 1)/alpha is sum(1 + 1/alpha) = 4 + sum(1/alpha). The sum of reciprocals of roots 1/alpha + 1/beta + 1/gamma + 1/delta is - (coefficient of x) / (constant term) = -(-7) / (-1) = -7. Thus, 4 + (-7) = -3.