Show that tan4x=sec2xtan2x+1-sec2x

What does the relationship between the mean and median reveal about the shape of the data

Julie goes to the sports store and spends $40.50 before tax. she buys a pair of shorts for $21.75 and 3 pairs of socks that each cost the same amount. how much does each pair of socks cost? $$

Plz ( true - false) all triangles have interior angles whose measure sum to 90.