Section B ( 54 marks ) 10 . Let f ( x) cos
4
� , x� . x
( a ) ( i ) Write down the range of the function f .
( ii ) Consider f( x) � 1, 0�x � 2π . Find the number of solutions to this equation . [ 5 ] p q
( b ) Find f� ( x) , giving your answer in the form asin xcos x where a , p , q� . [ 2 ]
( c ) Let g( x) � 2sin x for 0 �x
� π . Find the total area of the regions bounded by the graph of y � f ( x) g( x) and the x -axis. [ 7 ]
© SE Production Limited 16 All Rights Reserved 2021