What set of numbers does 8.1 belong to?

There is a line with slope 1/a going through the point (a, a²). find the equation of the line perpendicular to this line at this point. (don’t let this problem intimidate you! solve the problem as you would if i’d given you specific values. just use variables instead.)

What are the coordinates of the hole in the graph of the function f(x) ? f(x)=x2−9x−3 enter your answer in the boxes.

Three coins are flipped. what is the probability that there will be at least two tails?