It says...

Find the length fo the graph and compare it to the straight-line distance between the endpoints of the graph.

f(x)=ln[sex(x)] x E [0,(pi/4)]

how would you do this?

please help

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- October 22nd 2007, 11:27 AMrunner07Arc Length question
It says...

Find the length fo the graph and compare it to the straight-line distance between the endpoints of the graph.

f(x)=ln[sex(x)] x E [0,(pi/4)]

how would you do this?

please help - October 22nd 2007, 11:34 AMgalactus
ln(

**sex**)?. That's everyone's favorite integral:). What is E?.

Do you mean arc length of

If so,

- October 22nd 2007, 11:43 AMrunner07
oops. haha sorry about that. about the E, im not sure what it means. thats what it has in my book. it doesnt exactly look like an E though, its more curved than straight. it just says f(x)= ln[sec(x)], x E [0, (pi/4)]

but i think you're right. though when you take the derivative of sec(x) it equals sec(x)tan(x) right? i dont quite understand how you got tanx from ln[sec(x)] - October 22nd 2007, 11:58 AMgalactus
The derivative of ln(sec(x))=tan(x).

Chain rule:

The E may be 'element of'?. Is this it, ?.

If so, they just mean that's the limits of integration.

Which we found whittles down to something easy.

Once you find your solution to the integral, compare it to:

- October 22nd 2007, 06:20 PMrunner07
yeah! thats the E. but that makes more sense now. thank you so much!!