What is the discontinuity and zero of the function f(x) = the quantity of 3 x squared plus x minus 4, all over x minus 1? a. discontinuity at (-1, 1), zero at (four thirds, 0) b. discontinuity at (-1, 1), zero at (negative four thirds , 0) c. discontinuity at (1, 7), zero at (four thirds , 0) d. discontinuity at (1, 7), zero at (negtive four thirds, 0)

Researchers are conducting experiments to determine the role of alcohol in the development of depression. after the study is complete, they determine that the relative risk of developing depression is 1.55 with a 95 % ci of 1.2 -1.9. each group is then divided into nonsmokers and smokers. the relative risk for the nonsmokers is 1.12 with a 95% ci of 0.87-1.37. the relative risk for the smokers is 1.7 with a 95 % cl of 1.5-1.9. what type of bias may affect this study? a. procedure bias b. recall bias c. selection bias d. confounding e. lead-time bias