# Tough Possibly Long Cal I problem need help

• Mar 24th 2010, 07:38 PM
Fyou88
Tough Possibly Long Cal I problem need help
Estimate f(0.009) if f(x)=sin(sin(sin(5x)))/cos(sin(x)). (Wondering)
• Mar 24th 2010, 07:43 PM
pickslides
You could try $f(x+h)\approx f(x)+h\times f'(x)$
• Mar 24th 2010, 07:45 PM
Fyou88
what is that? limit definition?
• Mar 24th 2010, 07:53 PM
pickslides
No its a first order approximation.

It can estimate an answer for you.
• Mar 24th 2010, 07:55 PM
Fyou88
can u give an example of a problem using that formula i dunno how to use it?
• Mar 24th 2010, 07:58 PM
Fyou88
does this problem have anything to do with Trigonometric Functions or inverse Trigonometric Functions?
• Mar 24th 2010, 08:24 PM
pickslides
Quote:

Originally Posted by Fyou88
can u give an example of a problem using that formula i dunno how to use it?

Estimate $f(0.5)$ where $f(x) = \sin x$

$f(x+h)\approx f(x)+h\times f'(x)$

$f(x) = \sin x \implies f'(x) = \cos x$

$f(x+h)\approx \sin x+h\times \cos x$

Using $f(0.5) = f(0+0.5)$ i.e $x = 0,h=0.5$

$f(0+0.5)\approx \sin 0+0.5 \times \cos 0$

$f(0+0.5)\approx 0+0.5 \times 1 = 0.5$
• Mar 25th 2010, 08:01 AM
Fyou88
wow so means i have to find the derivative of sin(sin(sin(5x)))/cos(sin(x))? to get slope? and i would need chain rule??