+251 Instantaneous rate of change = \(f = \frac{f(x+h) - f(x)}{h} \)
Question: Find the instantaneous rate of change of y with respect to x for:
y= f(x) = 2x+3 when x = 4
it all seems pretty straight forward, but the solutions in the text book have as follows:
\([\frac{f(4+h) - f(4)}{h}]\)
= \([\frac{2(4+h)+3-11}{h}]\)
what I don't understand here is how the 11 came to be, I would have thought this step to be:
\([\frac{2(4+h)+3-2(4)+3}{h}]\)
Thank you for your help
+1491 The 11 came from x = 4 and f(4).
All that means is you plug in four for x into that funciton you were given.
f(4) = 2(4)+3
See?
Anymore questions? Just ask! (Not like l'm doing anything other than tearing my hair out from slope fields and Euler's method.)
+1491 Anyways what you have so far is pretty good. Derivatives by the definiton are a bit of a pain l'd rather not go back to.
+251 well that's a little embarrassing, i've just disregarded distrubtion...
thankyou for your help and also your quick responce.
good luck with your slopes, wish I could help
+1491 You really don't want to help. l'm pondering on dropping my class due to the difficulty of this segement. My love for math has died.
