- #1
Jacobpm64
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Find the equations of the tangent lines to the graph of [tex] f(x) = \sin x [/tex] at [tex] x = 0[/tex] and at [tex] x = \frac{ \pi }{3}[/tex]. Use each tangent line to approximate [tex] \sin( \frac{ \pi }{6} ) [/tex]. Would you expect these results to be equally accurate, since they are taken equally far away from [tex] x = \frac{ \pi }{6} [/tex] but on opposite sides? If the accuracy is different, can you account for the difference?
Here are my attempts:
Well, first let's find the equations of the tangent lines.
[tex] f(0) = \sin (0) = 0[/tex]
[tex] f(\frac{ \pi }{3}) = \sin( \frac{ \pi }{3}) = \frac{\sqrt{3}}{2} [/tex]
[tex] f'(x) = \cos (x) [/tex]
[tex] f'(0) = \cos (0) = 1 [/tex]
[tex] f'(\frac{ \pi }{3}) = \cos( \frac{ \pi }{3}) = \frac{1}{2} [/tex]
So we have (0,0), m = 1.
y = x <---- tangent line at x = 0.
And we have [tex] (\frac{ \pi }{3} , \frac{ \sqrt{3}}{2}) , m = \frac{1}{2} [/tex]
[tex]y = \frac{1}{2} x + \frac{3\sqrt{3} - \pi}{6} [/tex] <---- tangent line at [tex] x = \frac{ \pi }{3} [/tex]
Now we'll use the tangent lines to approximate [tex] \sin( \frac{ \pi }{6})[/tex].
Using y = x.
[tex]y(\frac{ \pi }{6}) = \frac{ \pi }{6} \approx 0.5236[/tex]
Using [tex] y = \frac{1}{2} x + \frac{3\sqrt{3} - \pi}{6} [/tex]
[tex]y(\frac{ \pi }{6}) = \frac{ \sqrt{3} }{2} - \frac{ \pi }{12} \approx 0.6042 [/tex]
They are obviously different. I don't know why they are different though.
Thanks in advance.
Here are my attempts:
Well, first let's find the equations of the tangent lines.
[tex] f(0) = \sin (0) = 0[/tex]
[tex] f(\frac{ \pi }{3}) = \sin( \frac{ \pi }{3}) = \frac{\sqrt{3}}{2} [/tex]
[tex] f'(x) = \cos (x) [/tex]
[tex] f'(0) = \cos (0) = 1 [/tex]
[tex] f'(\frac{ \pi }{3}) = \cos( \frac{ \pi }{3}) = \frac{1}{2} [/tex]
So we have (0,0), m = 1.
y = x <---- tangent line at x = 0.
And we have [tex] (\frac{ \pi }{3} , \frac{ \sqrt{3}}{2}) , m = \frac{1}{2} [/tex]
[tex]y = \frac{1}{2} x + \frac{3\sqrt{3} - \pi}{6} [/tex] <---- tangent line at [tex] x = \frac{ \pi }{3} [/tex]
Now we'll use the tangent lines to approximate [tex] \sin( \frac{ \pi }{6})[/tex].
Using y = x.
[tex]y(\frac{ \pi }{6}) = \frac{ \pi }{6} \approx 0.5236[/tex]
Using [tex] y = \frac{1}{2} x + \frac{3\sqrt{3} - \pi}{6} [/tex]
[tex]y(\frac{ \pi }{6}) = \frac{ \sqrt{3} }{2} - \frac{ \pi }{12} \approx 0.6042 [/tex]
They are obviously different. I don't know why they are different though.
Thanks in advance.
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