Prove this

1-tan^2x/1+tan^2x=cos^2x-sin^2x

Compare the subtraction problems 6/8 - 5/8 = 1/8 and 6/9 - 7/9 = 1/9 why is the answer to the first problem positive and the answer to the second problem negative

Last year, a state university received 3,560 applications from boys. of those applications, 35 percent were from boys who lived in other states. part a)how many applications did the university receive from boys who lived in other states? part b)applications to the university from boys represented 40percent of all applications. how many applications did the university receive in all? i don't how to do part b so me and plz tell how you got your answer

The table shows the age and finish time of ten runners in a half marathon. identify the outlier in this data set. drag into the table the ordered pair of the outlier and a reason why that point is an outlier.