- #1
Ocata
- 198
- 5
Homework Statement
[itex]\frac{d}{dx}7.5sin(\frac{pi}{10}x) [/itex]
The Attempt at a Solution
[itex]7.5(\frac{pi}{10})cos(\frac{pi}{10}x)[/itex]
Maximum: f'(x) = 0
[itex]7.5(\frac{pi}{10})cos(\frac{pi}{10}x)[/itex] = 0
[itex]7.5(\frac{pi}{10})cos^{-1}(0)= \frac{pi}{10}x[/itex]
**[itex] (\frac{pi}{10}\frac{10}{pi})7.5(90) = x[/itex]
[itex](1)(7.5)(90) = x = 675[/itex]
To me, this doesn't seem to be nearly the correct answer because it doesn't make sense given the graph of this function:
[itex]\frac{pi}{10}x= pi[/itex]
x = 10
So, the first arch is at x=0 and x = 10,
so the the maximum of the curve can not be x = 675.
What am I doing incorrectly in the derivative of the trigonometric function?
Thank you