SOLUTION: What is the period of f(x) = cot(4x)+7

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Question 968429: What is the period of f(x) = cot(4x)+7
Found 2 solutions by lwsshak3, Theo:
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
What is the period of f(x) = cot(4x)+7
ans: π/4

Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
the normal period of cot(x) would be pi.
this is because the graph repeats every pi units on the x-axis.
the graph of cot(x) is shown below:

$$$

the period of cot(4x) would be pi/4.
this is because the graph repeats every pi/4 units on the x-axis.
the graph of cot(4x) is shown below:

$$$

period for sine and cosine and secant and cosecant function = 2pi / frequency

frequency for sine and cosine and secant and cosecant function = 2pi / period.

period for tangent and cotangent function = pi / frequency.

frequency for tangent and cotangent function = pi / period.

in your probolem, the frequency of the cotangent function is 4.

this makes the period pi/4.

if you were given the period as pi/4, then the freq8uency would be calculated as pi / (pi/4) which would then become 4.

the general formula for repeating trigonometric functions is

y = a*sin(b*(x-c))+d

a is the amplitude.
b is the frequency
c is the horizontal displacement.
d is the vertical displacement.

your equation would be shown as:

y = a*cot(b*(x-c)+d

in your equation:
a = 1
b = 4
c = 0
d = 7

your amplitude is 1.
your frequency is 4
your horizontal displacement is 0.
your vertical displacement is 7.

vertical displacement means that your center line for the graph will be 7 units above the x-axis.

here's the graph of y = cot(4x).

graph%28400%2C400%2C-2%2C2%2C-15%2C15%2C1%2Ftan%284x%29%2C0%29

here's the graph of y = cot(4x) + 7

graph%28400%2C400%2C-2%2C2%2C-15%2C15%2C1%2Ftan%284x%29%2B7%2C7%29

you can see that the centerline for the grpah has been vertically displaced by 7 units in a positive direction.

here's a couple of references for you to ponder.

http://www.regentsprep.org/regents/math/algtrig/att7/sincostan.htm

http://www.regentsprep.org/regents/math/algtrig/att7/othergraphs.htm

note that the normal period for sine and cosine is shown as 2pi and the normal period for tangent and cotangent is shown as pi.