Which expression has the same value as the one below? V
8+ [4+(-9)]
o 12+(-9)
O-12+9
O-4+(-9)
04+(-9)

Sketch one cycle if the cosine function y=2cos2theta

In a test for esp (extrasensory perception), a subject is told that cards only the experimenter can see contain either a star, a circle, a wave, or a square. as the experimenter looks at each of 20 cards in turn, the subject names the shape on the card. a subject who is just guessing has probability 0.25 of guessing correctly on each card. a. the count of correct guesses in 20 cards has a binomial distribution. what are n and p? b. what is the mean number of correct guesses in 20 cards for subjects who are just guessing? c. what is the probability of exactly 5 correct guesses in 20 cards if a subject is just guessing?

The triangles are similar. what is the value of x? enter your answer in the box.