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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Mathematical Methods CAS => Topic started by: This-is-not-me on May 30, 2013, 06:11:16 pm

Title: Circular Functions 'strictly decreasing' question?
Post by: This-is-not-me on May 30, 2013, 06:11:16 pm: Can someone please explain part c.) of this question to me?
I've never seen one like it and I'm totally confused -.-
Title: Re: Circular Functions 'strictly decreasing' question?
Post by: BubbleWrapMan on May 30, 2013, 06:24:21 pm: You got the right answer. The period is 60, though.
Title: Re: Circular Functions 'strictly decreasing' question?
Post by: This-is-not-me on May 30, 2013, 06:40:07 pm: Yeah I wrote the period down wrong. But my teacher didn't give me the mark for part c.), any idea why?
Title: Re: Circular Functions 'strictly decreasing' question?
Post by: BubbleWrapMan on May 30, 2013, 06:41:49 pm: Not the slightest.
Title: Re: Circular Functions 'strictly decreasing' question?
Post by: Daenerys Targaryen on May 30, 2013, 06:51:39 pm: maybe you needed $x\in [15,45]$
Title: Re: Circular Functions 'strictly decreasing' question?
Post by: This-is-not-me on May 30, 2013, 06:59:14 pm: wow if that's the reason than I absolutely hate my teacher, this was a sac and I reckon he should of been more lenient :(
Title: Re: Circular Functions 'strictly decreasing' question?
Post by: BubbleWrapMan on May 31, 2013, 05:02:09 pm: The definition of a function $f$ being strictly increasing on an interval $[a,b]$ is that for all $x_{1},x_{2}\in [a,b]$ , $x_{2}>x_{1}\implies f(x_{2})>f(x_{1})$ . So it can include stationary points.
Title: Re: Circular Functions 'strictly decreasing' question?
Post by: FlorianK on June 02, 2013, 05:34:45 am: Quote from: HatersGonnaHate on May 30, 2013, 06:51:39 pm
maybe you needed $x\in [15,45]$
this is really the only possible reason. I would talk to the teacher again
Title: Re: Circular Functions 'strictly decreasing' question?
Post by: This-is-not-me on June 02, 2013, 04:50:09 pm: haha thanks and I did, turns out that he did in fact mark it incorrectly and I did get my mark.
Thanks everyone.
Title: Re: Circular Functions 'strictly decreasing' question?
Post by: BubbleWrapMan on June 02, 2013, 04:59:18 pm: Quote from: This-is-not-me on June 02, 2013, 04:50:09 pm
haha thanks and I did, turns out that he did in fact mark it incorrectly and I did get my mark.
Thanks everyone.
Justice!
Title: Re: Circular Functions 'strictly decreasing' question?
Post by: FlorianK on June 02, 2013, 07:01:04 pm: Quote from: This-is-not-me on June 02, 2013, 04:50:09 pm
haha thanks and I did, turns out that he did in fact mark it incorrectly and I did get my mark.
Thanks everyone.

Great :). Next time I would still include the $x\in$ though :D
Title: Re: Circular Functions 'strictly decreasing' question?
Post by: This-is-not-me on June 05, 2013, 10:21:53 pm: Yeah I will :) thanks