Which of the following are identities? Check all that apply.
A. sin(x + y) - sin(x - y) = 2 cosx siny
B. cos(x + y) + cos(x - y) = cos? x- sin? y
C. cos(x+y)+cos(x - y) = 2cos x cosy
D. sin(x - 1) = - sinx

What are “like terms”? why can we only add like terms?

Typically a point in a three dimensional cartesian coordinate system is represented by which of the following answers in the picture !

Now, martin can reasonably guess that the standard deviation for the entire population of people at the mall during the time of the survey is $1.50. what is the 95% confidence interval about the sample mean? interpret what this means in the context of the situation where 95 people were surveyed and the sample mean is $8. use the information in this resource to construct the confidence interval.