0/2011 (a)
Prove that cos3x = 4cos'x - 3cos x. Hence, show that
cos2x =-(cos 6x + 3cos 2x).
(b)
[4 marks]
Use the above identity to find all the solutions in the interval
-180° <x<180° of the equation 2 cos 3x + cos2x+1= 0. [7 marks]

Beatrice decides she wants to babysit a few children at the same time to earn the money faster. she tells parents that if they allow her to babysit their children at her house, she will eliminate her automatic $5 tip and will give them an additional $5 discount. (a) write an equation showing the total cost for each client. identify all variables. (b) four parents bring their children to beatrice’s house at the same time for babysitting. beatrice wants to find out how many hours she must babysit the 4 children to earn exactly the $100 she needs in order to buy the present for her mother. write and solve an equation to find the number of hours. justify each step in the solution. (c) one parent decides not to drop off her child. the remaining 3 parents drop their children off at 9 a. m. two of the parents say they will be back at 1 p. m. the third parent says she will pick up her child at 2 p. m. at noon, beatrice realizes she needs feeding the 3 ch

The marriott family bought a new apartment three years ago for $65,000. the apartment is now worth $86,515. assuming a steady rate of growth, what was the yearly rate of appreciation? what is the percent of the yearly rate of appreciation?

Question: a) does the given set of points represent a linear function? how do you know? b) assume that the point (-2,4) lies on the graph of a line. what y-values could complete this set of ordered pairs that lie on the same line: (- (hint: there are several correct answ