Tangent lines of trigonometric functions

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Discussion Overview

The discussion revolves around finding the equation of the tangent line to the curve defined by the function \(y=\sec(x)\) at the point \((\pi/3, 2)\). Participants explore the process of differentiation and the application of the tangent line formula, focusing on the mathematical steps involved in reaching the solution.

Discussion Character

  • Homework-related
  • Mathematical reasoning

Main Points Raised

  • One participant presents their work on finding the tangent line, including the derivative \(y'=\sec(x)\tan(x)\) and the calculation of the slope at the specified point.
  • Another participant confirms the correctness of the first participant's final expression for the tangent line, reiterating the equation provided.
  • A subsequent reply also agrees with the correctness of the first participant's work, expressing appreciation for the prompt response.
  • A later post offers tips on improving the presentation of mathematical expressions using \(\LaTeX\), suggesting various formatting techniques without addressing the correctness of the mathematical content itself.

Areas of Agreement / Disagreement

There is general agreement among participants regarding the correctness of the initial participant's approach and final expression for the tangent line. However, the discussion does not explore any alternative methods or solutions, leaving the topic primarily focused on the presented work.

Contextual Notes

Participants do not address any potential limitations or assumptions in the problem, nor do they explore the implications of using different methods for finding the tangent line.

Petrus
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Hello,
I got problem with A homework
"find an equation of the tangent line to curve at the given point.
$y=sec(x)$. $(pi/3,2)$
progress:
$y'=sec(x)tan(x)$. So basically that sec(x) don't say me much so i rewrite it as $1/cos(x)$
$y'=1/cos(x)•tan(x)$ now i can put $pi/3$ on the function to calculate the slope.
i get that the slope is $m=2•sqrt(3)$ and now we use the tangent equation $y-y1=m(x-x1)$
So we got $y-2=2sqrt(3)(x-pi/3)$ and i basically answer $y=2sqrt(3)(x-pi/3)+2$
Is this correct? I am sure i am thinking correct but not 100%
 
Last edited:
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Re: Tangent of trigonometric functions

Yes, you are correct! (Clapping) I assume your last expression was

$$y = 2 \sqrt{3} \left( x - \frac{\pi}{3} \right) +2.$$
 
Re: Tangent of trigonometric functions

Fantini said:
Yes, you are correct! (Clapping) I assume your last expression was

$$y = 2 \sqrt{3} \left( x - \frac{\pi}{3} \right) +2.$$
Yes:) Thanks for the fast responed!:)
 
Re: Tangent of trigonometric functions

You are welcome! Keep on the right track, focusing on the concepts. (Yes)
 
Re: Tangent of trigonometric functions

Petrus said:
Hello,
I got problem with A homework
"find an equation of the tangent line to curve at the given point.
$y=sec(x)$. $(pi/3,2)$
progress:
$y'=sec(x)tan(x)$. So basically that sec(x) don't say me much so i rewrite it as $1/cos(x)$
$y'=1/cos(x)•tan(x)$ now i can put $pi/3$ on the function to calculate the slope.
i get that the slope is $m=2•sqrt(3)$ and now we use the tangent equation $y-y1=m(x-x1)$
So we got $y-2=2sqrt(3)(x-pi/3)$ and i basically answer $y=2sqrt(3)(x-pi/3)+2$
Is this correct? I am sure i am thinking correct but not 100%

Hello Petrus,

Great job in presenting the problem and showing your progress! This is what we like to see.

In order to help you improve the look of your presentation, I want to offer you some tips on using $\LaTeX$.

For trigonometric (or other) functions precede them with a backslash, e.g.:

y=\sec(x) will produce $y=\sec(x)$

For special characters like the symbol for the Greek letter pi, precede this also with a backslash:

\pi will produce $\pi$

To express a fraction, use the \frac{}{} command:

\frac{\pi}{3} will produce $\frac{\pi}{3}$

To make the fraction larger, use either of the following:

\dfrac{\pi}{3} will produce $\dfrac{\pi}{3}$

\displaystyle \frac{\pi}{3} will produce $\displaystyle \frac{\pi}{3}$

Using \displaystyle will make all fractions, integrals, sums, etc. look better in your entire expression.

To enclose a composite expression containing "tall" expressions within parentheses, use \left( \right) and the parentheses will be automatically generated to be tall enough to enclose the expression:

\displaystyle \left(\frac{\pi}{3},2 \right) will produce $\displaystyle \left(\frac{\pi}{3},2 \right)$

To produce the "dot" multiplication symbol use the command \cdot, for example:

\displaystyle y'=\frac{1}{\cos(x)}\cdot\tan(x) will produce $\displaystyle y'=\frac{1}{\cos(x)}\cdot\tan(x)$

To produce the square root symbol, use the command \sqrt{}, e.g.:

m=2\cdot\sqrt{3} will produce $m=2\cdot\sqrt{3}$

To use subscripts, use the underscore character, for example:

y-y_1=m(x-x_1) will produce $y-y_1=m(x-x_1)$

As a last note, if you see a nice expression written in $\LaTeX$ by someone else, and you wish to see the code they have used, right-click on the expression, and on the pop-up menu, choose Show Math As and TeX Commands and a window will pop up showing you the commands used to produce the expression.

Happy TeXing! (Yes)
 

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