Section 6 (Graphs of Other Trig Fcns)

Nov 6th, 2010 by corricelli

Hello Teams 2 and 7,

Let’s use this spot to post questions for Honors Precalculus, Unit 4, Section 6!

Happy blogging,
Mrs. Corricelli

6 Responses to “Section 6 (Graphs of Other Trig Fcns)”

Colleen Lynch says:

November 22, 2010 at 7:17 pm

I am completely lost on number 51. Anyone have any suggestions because I looked up the work on clac chat but it wasn’t much help

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Becca van Stolk-Cooke says:

November 22, 2010 at 7:34 pm

Hey colleen I wish I could help but im lost too. I’m confused on 35 basically onward. I understand that to fine cosec i need to graph the sin, but I’m having a hard time with that too.

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Colleen Lynch says:

November 22, 2010 at 7:50 pm

Alright it might help to write out all the portions of the graph sin aka the ampitude period and phshfit and then find the start and end of one period.
So y=2cos(x+pi)
a=2, b=1, and c= -pi
so the amplitude is 2 the period is 2pi because you use 2pi/b and the phshift is -pi because it is c/b

Then I found the start and end
x+pi=0
x=negativepi and the end x+pi=2pi
so x=pi

From there you should beable to graph sin knowing that it starts with a max, int, min, int, max for one period.

After that I drew dotted lines through the intersepts because they are asympotes in y=2sec(x+pi). Then I drew curves starting at the maxes and mins.

I don’t know if that would help and if it doesn’t try looking up the answer on clac chat because the work there might be more clear than mine

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Colin Kuntz period 6 says:

November 22, 2010 at 9:57 pm

Colleen, for 51 you need to graph y=cotx and then find at which points cotx = -sqrt(3)/3 between [-2pi, 2pi]. I hope this helps but if you’re still having trouble try graphing y=cotx and y=-sqrt(3/3) in the same window and look at the intersection points.

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Will Thomas says:

November 22, 2010 at 11:28 pm

how do you know what bx-c equals for each of the different graphs? i know bx-c=2pi and 0 for sine and cosine functions, but what is on the right side for the others? is it the period and zero?

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corricelli says:

November 23, 2010 at 7:47 pm

OK Will:

For each trig function, bx-c = “a number” to get the start of the curve. This could be anywhere; we just pick convenient places.

In sin(x), bx-c = 0 to get the start of the curve, which will be an intercept.
In cos(x), bx-c = 0 to get the start of the curve, which will be a min if a<0 or a max if a>0.
In tan(x), bx-c = -pi/2 to get the start of the curve, which will be an asymptote.
In cot(x), bx-c = 0, to get the start of the curve, which will be an asymptote.
csc(x) and sec(x) are graphed relative to sine and cosine, respectively.

Hope this helps,
Mrs. Corricelli

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