Question

If alpha and beta are the roots of quadratic equation x²-2x-7=0
find the value of α²+β²

Answer 1

18 is the answer
......hope it helps

Answer 2

Answer:

18

Step-by-step explanation:

$\alpha + \beta = \binom{ - b}{1} \\ \alpha + \beta = - \binom { - 2}{1} \\ = 2 \\ \alpha \beta = \binom{c}{a} \: \\ \alpha \beta = \binom{ - 7}{1} \\ = - 7 \\ { \alpha }^{2} + { \beta }^{2} \\ ( { \alpha + \beta )}^{2} - 2 \alpha \beta \\ {2}^{2} - 2 - 7 \\ 4 + 14 \\ = 18$