How do you find period, amplitude, phase shift and midline of f(x) = −4 sin(2x + π) − 5?

1 Answer
Jun 10, 2018

please see below

Explanation:

we have standard form
asin(bx+c)+-d
|a| " is amplitude," (2pi)/|b|" is period," " c is phase shift (or horizontal shift), d is vertical shift"
comparing the equation with standard form
a=-4,b=2,c=pi,d=-5

midline is the line that runs between the maximum and minimum value(i.e amplitudes)
since the new amplitude is 4 and graph is shifted 5 units in negative y-"axis" (d=-5)

therefore maximum value is 4-5=-1 and minimum value is -4-5=-9 midline will be centre of the region(-1,-9)" " i.e" "-5

phase change =pi units right(c is positive)
period is (2pi)/2=pi

it will be more clear from graph
graph{-4sin(2x+pi)-5 [-16.02, 16.01, -8.01, 8.01]}