Explain why cos (-3pi/4) = cos (5pi/4)

The size of a certain cell is 2.5*10^-9m. another cell is 1.5*10^3 times larger. how large is the larger cell in scientific notation?

For a science project, a high school research team conducted a survey of local air temperatures. based on the results of the survey, the found that the average temperatures were around 10 degrees higher than expected. this result was wrong. the trouble with the survey was that most of the locations were exposed to direct sunlight and located over asphalt or sand, which resulted in higher temperatures than normal. this is a classic example of an error in which phase of inferential statistics?

Answer 20 points and brainiest ! on the board, your teacher writes an example of how to find the median. one of the numbers is erased, leaving what is shown, 18, 30, 26,12 22. what is the median? a. 10 b. 20 c. 24 d. 28