Estou estudando função quadrática e, me confundo bastante na resolução do gráfico, a conta de bháskara eu faço com facilidade, mas quando não existem números suficientes para atribuir a "b" e "c", por exemplo, b²-4ac, eu não sei realmente aplicar o calculo -b\2a, e para piorar, quando o professor passou esse matéria em aula on-line, a internet tinha caído no meu bairro. Alguém pode me explicar?

If your score on your next statistics test is converted to a z score, which of these z scores would you prefer: minus2.00, minus1.00, 0, 1.00, 2.00? why? a. the z score of 2.00 is most preferable because it is 2.00 standard deviations above the mean and would correspond to the highest of the five different possible test scores. b. the z score of 0 is most preferable because it corresponds to a test score equal to the mean. c. the z score of minus2.00 is most preferable because it is 2.00 standard deviations below the mean and would correspond to the highest of the five different possible test scores. d. the z score of minus1.00 is most preferable because it is 1.00 standard deviation below the mean and would correspond to an above average