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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Mathematical Methods CAS => Topic started by: Walzzy on September 20, 2011, 05:37:06 pm

Title: Insight MM CAS 2011 Exam 1 Question 4a)
Post by: Walzzy on September 20, 2011, 05:37:06 pm

Hey guys. the question asks you to sketch a trig function simple enough, |2cos(2x)-1|. i want to know if there are any axis intercepts other than coordinate (0,1). i dont have answers and want to know.

Title: Re: Insight MM CAS 2011 Exam 1 Question 4a)
Post by: luken93 on September 20, 2011, 05:39:50 pm

Axial intercepts for a modulus will be the same as it being a normal function, as it is reflected ON the y axis...

Title: Re: Insight MM CAS 2011 Exam 1 Question 4a)
Post by: Walzzy on September 20, 2011, 05:57:56 pm

My calculator said no roots where found. (i know i wasent supposed to use it h3h3h3)

Title: Re: Insight MM CAS 2011 Exam 1 Question 4a)
Post by: azn_dj on September 20, 2011, 06:17:41 pm

Can you screen shot the question so I can have a look at it? (it's less than 10% of the entire exam so yes, it is legal)

Title: Re: Insight MM CAS 2011 Exam 1 Question 4a)
Post by: Walzzy on September 20, 2011, 10:46:15 pm

I only have a physical copy, sorry

Title: Re: Insight MM CAS 2011 Exam 1 Question 4a)
Post by: nna_aka_ann on September 23, 2011, 06:15:09 pm

Hi,
Hopefully this is helpful. :)
Simply its sketching y=2cos(2x)-1 and refecting anything beneath the x-axis so all of it is above it.

Title: Re: Insight MM CAS 2011 Exam 1 Question 4a)
Post by: simon_93 on September 23, 2011, 06:41:04 pm

The above post explains the question pretty well.
There are also x-intercepts at (-5π/6, 0) and (-π/6,0), as the domain is from -pi to pi, inclusive.
If you require the solutions to any other questions on that paper, feel free to ask :)