What is the amplitude, period, and phase shift of
f(x) = −4 sin(2x + π) − 5?

Question

What is the amplitude, period, and phase shift of 
f(x) = −4 sin(2x + π) − 5?

anonymous · Answer

@jim_thompson5910

jim_thompson5910 · Answer

y = A*sin(Bx - C) + D

is the general equation of sine

with these properties


Amplitude: |A|

Period: T = 2pi/B

Phase Shift: C/B

Midline: y = D

anonymous · Answer

So, in theory, the correct answer would be 4, pi, and pi/2?

jim_thompson5910 · Answer

first two are correct but pi/2 is not the phase shift

jim_thompson5910 · Answer

think of 2x + π as 2x - (-π) and compare that with Bx - C

anonymous · Answer

-pi/2?

jim_thompson5910 · Answer

better

C = -pi
B = 2

anonymous · Answer

Wait.... I got it correct?

anonymous · Answer

I'm sorry, your wording of "better" confused me.

jim_thompson5910 · Answer

you did

jim_thompson5910 · Answer

I meant you did better in saying -pi/2 is the answer

anonymous · Answer

Thank you!  Would you possibly mind helping me with one more?

anonymous · Answer

Oh, that makes sense :)

anonymous · Answer

In Pensacola in June, high tide was at noon. The water level at high tide was 12 feet and 2 feet at low tide. Assuming the next high tide is exactly 12 hours later and that the height of the water can be modeled by a cosine curve, find an equation for water level in June for Pensacola as a function of time (t).