Re: Please help me out I am stuck!
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Re: Please help me out I am stuck!
Eva Hellqvist writes:
> Could someone please help me out on these.
>
> 1) How do I find the lowest positive root of Y=2-3*SIN(0.5*X)
>
> I can see it on the plotter but I cant do it on paper.
You don't say what kind of calculator you are using, so I can't say anything
about the mechanics involved. You are apparently searching for a zero of this
function, or a root of the equation 0 = 2 - 3sin(x/2). This one is simple
enough to solve "by inspection" -- should be twice the arcsine of 2/3 -- but a
very slight change in the problem would make solution by inspection (or pencil
and paper) impossible, so it is appropriate to consider how to apply graphing
calculator techonology. One of the CALC tools ought to do it -- "zero" on the
TI-83, for example or "root" on the TI-85, you specify the search interval and
an initial estimate, and the calculator does the rest.
> 2) a) Solve TAN(3*V+300) = -0.2 in the interval 1800 < or = V < or = 2700
>
> b) Using the equation calculate the exact value of TAN 150
To start, multiply the inequality by 3 and add 300 to get an idea of what
inputs to tan should be considered (I assume you are talking degrees). There
should be several solutions, which you could track down by using your
calculator. One way would be to find the zeros of y = 0.2 + tan(3v + 300) in
that range.
I don't offhand see the relevance of the question in part b) to the
calculation in part a). If you are talking degrees, it's easy to relate
tan(150) to tan(30), for which an exact value can be calculated by elementary
geometry. This is all good mathematics. What is it from, if I may ask?
RWW Taylor
National Technical Institute for the Deaf
Rochester Institute of Technology
Rochester NY 14623
>>>> The plural of mongoose begins with p. <<<<