I have a maths exam tomorrow, so I would be grateful for any help!
So here it is:
Let f(t) = a cos b(t-c) + d (I understand that this refers to the transformation)
when t = 3, there is a maximum value of 29,
when t = 9, there is a minimum value of 15.
Find the value of a.
I got as far as:
29 = a cos 3t
15 = a cos 9t
Is that right? And how should I find a?