A Turing machine with doubly infinite tape is similar to an ordinary Turing machine, but its tape is infinite to the left as wellas to the right The tape is initially filled with blanks except for the portion that contains the input. Computation is definedas usual except that the head never encounters an end to the tape as it moves leftward. Show that this type of Turingmachine recognizes the class of Turing- recognizable languages.

The blue whale is the largest animal living on the earth. the average blue whale measures 100 feet long (30 meters) and weighs 300,000 pounds (136,000 kilograms). a whale’s head is 1⁄3 of the length of its body. a new baby whale is 1⁄4 the length of a grown whale. the average man is 1⁄17 the length of a blue whale, and 1⁄1,818 its weight. a human baby measures 1⁄4 of the length of an adult. calculate the following information: how long is a whale’s head? how long is a new baby whale? how tall is the average man? how much does the average man weigh? how tall is the average human baby?

Each morning papa notes the birds feeding on his bird feeder. so far this month he has see. 59 blue jays, 68 black crows, 12 red robin's and 1 cardinal. what is the probability of a blue jay being the next bird papa sees

Which property was used to simplify the expression? 3c+9 +4c=3c+4c+9