What is the value of b2 - 4ac for the following equation?

2x^2 - 2x - 1 = 0​

Plot the intercepts to graph the equation

With number 11 ( show how you got the answer)

The birth weights of newborn babies in the unites states follow in a normal distrubution with a mean of 3.4 kg and standard deviation of 0.6 kg. reaserches interested in studying how. children gain weights decide to take random samples of 100 newborn babies and calculate the sample mean birth weights for each sample