Mrs. thomas bought a bed for $1,548 and three armchairs. the bed cost 4 times as much as one armchair. how much did mrs. thomas spend altogether?

Researchers were interested in whether relaxation training decreases the number of headaches a person experiences. they randomly assigned 20 participants to a control group or a relaxation training group and noted the change in number of headaches each group reported from the week before training to the week after training. which statistical analysis should be performed to answer the researchers' question?

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

What’s the range cuz i can’t find it?