show that the derivatives of sinx and cosx can be computed for all values of x if we know the derivative at just one place, x = 0.

Question

ganeshie8 · Answer

Wanna try this @Nnesha ? :)

nnesha · Answer

beyond my knowledge..haha

daniel.ohearn1 · Answer

Well the period of both functions is 2π, at π we find the inflection point of the wave  by definition of sin(x) and cos(x).  This remains true at the limit as h approaches 0 of (f(x+h)+f(x))/ h  definition of the derivative.

ganeshie8 · Answer

Hmm interesting... could you pls elaborate on how inflection points help here  ?
@daniel.ohearn1

yumyum247 · Answer

GOD!!

ganeshie8 · Answer

@Nnesha this may not be too much hard if you start at the right place... 
Here is another way to ask the question :

Suppose I give you the slope of below green tangent lines to the graphs of sinx and cosx at x = 0. Can you device a method to figure out the slope of tangent line to the curves at every other point ?

|dw:1464326380981:dw|