Tangents
 

http://www.cox-internet.com/ashish/problem.jpg

I cant seem to figure this one out.

The fact that h is approaching zero keeps throwing me off.

This is why I don't take college-level math.

kinda sux when u have to :(

EDIT : I Figured it out!

seems that 4 is the slope, and all u gotta do is to put it into slope intercept form.

i was thinking too hard!

and the answer is -15 if anyone is wondering

What you are doing is using the long-form differentiation method to evaluate the derivative of f(x) when x=4.

Long story short: the derivative of a function gives you the slope at point (x,y) [plug x into the derivative f ' (x)] and plug x into f(x) to get "y".

the point-slop form y=mx+b is useful, however, also consider: y-y1 = m(x-x1) + b in the future.

hrmm.. unless I misunderstood your post Sapper, there is a very miniscule flaw. Just wanted to point out that y=mx+b is considered slope-intercept form, and that the other equation you stated was point-slope form. I know it's nothing big, but just thought I'd clarify that incase anyone got confused. :-)

So true ... it's been awhile since I've had to consider the names of functions. In fact, for the first time in ages, I actually had to remember the intermediate value function in relation to infinity. So fundamental that I "just knew" the application .. but could not remember the proper name.

As a double check, you might want to consider getting a Ti-89 graphing calculator. Will differentiate, integrate, and take limits symbolically. Wont help you learn the stuff, but its great to be able to check your answer before you have to hand something in or on a test.

Is the TI-89 the one you can download Tetris onto ??

lol ...

:D

You guys are making my brain bleed...

:(

Mr Mephisto