Cos² 2x = (1+cos 4x )/2
cos² 6x = (1+cos 12x)/2
subtract to get 1/2 (cos 4x - cos 12x )
= 1/2 (2 sin 4x sin 8x ) as cos A - cos B = 2 [ sin (A+B)/2 sin (A-B)/2 ]
so the answer
Answer:
663
Step-by-step explanation:
the total number of students can be determined using this equation :
(total ratio of Chinese and Indian students / total ratio of students) x n = 468
total ratio of Chinese and Indian students = 4 + 8 = 12
total ratio of students 4 + 8 + 5 = 17
N = TOTAL NUMBER OF STUDENTS
12/17) x n = 468
multiply both sides of the equation by 17/12
n = 663
5.5% as a multiple is 0.055
So 700 x 0.055= $38.50 in commission
475 (standard pay) + 38.50 (commission) = $513.50 in that week
