find the derivative of 2-5x using the limit definition. Which I believe to be (f(x+h)-f(x))/h.

Question

luffingsails · Answer

Don't forget about the part where h->0 once you are finished. <laugh>

The key christal is to do exactly what you have written for the equation you are given. Then to take the limit as h->0.

f(x+h) = 2-5(x+h)
f(x) = 2-5(x)

Substitute, simplify and take the limit. Give it a try and see where it takes you.

anonymous · Answer

i tried and i got -5(2x+h)/h

whpalmer4 · Answer

$$ f(x) = 2-5x,  f(x+h) = 2-5(x+h) = 2 - 5x - 5h$$

$$\lim_{h \rightarrow 0} ((2-5x-5h) - (2-5x))/h =  \lim_{h \rightarrow 0} -5h/h = -5$$

anonymous · Answer

oh okk for some reason i didnt cancel out the 5x's. thanks!