Help with applying sine and cosine functions

Question

anonymous · Answer

Post the problem

darkbluechocobo · Answer

The function $$f(x)=0.6\sin(x\frac{ 2\pi }{ 5 })$$ represents the velocity of air flow of normal breathing cycles, where x is measured in seconds. A cycle consists of inhaling, where air flow is positive, and exhaling where air flow is negative. The air flow is measured in liters per second. During the first cycle of breathing, when will the air flow be at its maximum and what will the air flow be at that point in time?

anonymous · Answer

@Luigi0210

darkbluechocobo · Answer

@campbell_st

campbell_st · Answer

I'd probably find the 1st derivative and solve for x. then that would be the time of the max air flow. 

when you find x substitute it into the original equation to find the flow

darkbluechocobo · Answer

I have heard about this method but I have not been taught this