Answer:
Step-by-step explanation:
(cos7A + cos3A - cos5A - cosA)÷(sin7A - sin3A - sin5a + sinA)
By using transformations,
[(cos7A - cos5A) + (cos3A - cosA)]÷[(sin7A - sin5A) - (sin3A - sinA)]....
we get...
=[(2sin6A.sinA)+(2sin2A.sinA)]÷[(2cos6A.sinA)-(2cos2A.sinA)]...
=[{2sinA(sin6A+sin2A)}]÷[{2sinA(cos6A-cos2A)]
=[{2sin4A.cos2A}÷{2sin4A.sin2A}]
=[(cos2A)÷(sin2A)]
=cot2A
90/5=18
18 books per shelf
18*14=252
252 books on 14 shelves
Answer:
9:12
Step-by-step explanation:
since the others are multiples of 2:3
but 9:12 is not a multiple
QUESTION 1: The answers are GEOMETRIC and 256.
QUESTION 2: The answer is 3.
QUESTION 3: The answer is tn = -9n + 42
QUESTION 4: The answer is tn = 2n + 4
QUESTION 5: The answer is tn = 1*3^(n-1) (THE SECOND CHOICE)
QUESTION 6: The answer is tn = 1*(1/2)^(n-1) (THE THIRD CHOICE)
QUESTION 7: The answer is 26.
QUESTION 8: The answer is 3.