Given y=-6cos((-4pi/3)x)?

Question

(a) simplify

(b) state amplitude and period

Answer 1

(a)

cos (-x) = cos x                                 [ since cos is a even function ]

Answer 2

(b)

cos (-x) = cos x                                 [ since cos is a even function ]

Now compare  and   .

Amplitude = │a│

               =│-6│

               = 6

So the  amplitude is 6 .

The  period is  .

So the period of the function is 3/2 .