Solving Problems Using Sinusoidal Models Part 1

This lesson shows how to model some periodic phenomena using sinusoidal functions. This is the first part of a two part lesson. This lesson was created for the MCR3U Functions course in the province of Ontario, Canada.

[AlRichards]

@contractkilla24 You can always use either cosine or sine. All that changes is what the phase shift or horizontal transation is. My rule of thumb is that if a graph starts at the origin then use sine and if it starts at a max point at 0 then use cosine.

[AlRichards]

@youhendrytube Yes, you are correct. There are really an infinite number of phase shifts possible so your suggestion is another equation that could be used to model this graph.

[InfinitelyManic]

Good video. I learned this using a slightly different approach, which resulted in a sin model (in radians) as follows:

y=25Sin(2Pi/1.6x-Pi/2)+50.

[youhendrytube]

can we say that the phase shift is 2.4 sec right (cos) taken from the 2nd cos peak point

so that makes the equation become h = 25 cos (360/1.6)(t-2.4)+50

is that working also?