An IT shop sells laptops, tablets, and mobile phones The composite bar chart shows information on sales over the last three years.
C) which of the items increased in sale over the last three years?
Give a reason for your answer.

-7/8

step-by-step explanation:

instead of subtracting you add the -6/8 and -1/8

correct answer is b. 27/8

step-by-step explanation:

answer: cos [   arcsin (3/5) - arccos (1/2) ] =

step-by-step explanation: × = 3/5 = 0.6--> x = 36.87 and x = 180 - 36.87 = 143.13 deg

cos y = 1/2 --> y = +- 60 deg a. cos (x - y) = cos (143.13 - 60) = cos 83,13  

=

0.12

b. cos (36.87 - 60) = cos (-23.23) = 0.92