SPM Additional Mathematics 2018, Paper 2 (Question 7 – 9)

Question 7 (10 marks): ( a ) Prove sin( 3x+ π 6 )−sin( 3x− π 6 )=cos3x ( b ) Hence, ( i ) solve the equation sin( 3x 2 + π 6 )−sin( 3x 2 − π 6 )= 1 2  for 0≤x≤2π  and give your answer in the simplest fraction form in terms of π radian. ( ii ) sketch the graph of y=sin( 3x+ π 6 )−sin( 3x− π 6 )− 1 2  for 0≤x≤π. Solution: ( a ) Left hand side, … Read more