







Derivées partielle 
19991019 

Arnaud Flandin pose la question : Quel est la definition des derivées partielle Claude Tardif lui répond. 





Heat equation 
20171123 

Max pose la question : What does du\dt=a(triangle)^2u mean. Can it be solved for t. Penny Nom lui répond. 





Differentiate ln[x(2x4)^1/2] 
20140628 

Igwe pose la question : If y=In[x(2x4)^1/2],find dy/dx at x=3 Penny Nom lui répond. 





Differentiation rules 
20121023 

Morgan pose la question : Use the derivative rules to differentiate each of the following:
1. f(x)=1/x1 2. f(x)= sqrt(x) Penny Nom lui répond. 





Partial derivatives 
20090117 

Meghan pose la question : I have a question I've been working at for a while with maxima/minima of partial derivatives.
"Postal rules require that the length + girth of a package (dimensions x, y, l) cannot exceed 84 inches in order to be mailed.
Find the dimensions of the rectangular package of greatest volume that can be mailed.
(84 = length + girth = l + 2x + 2y)" Harley Weston lui répond. 





Implicit Derivatives 
20070713 

Charles pose la question : I need help computing y' by implicit differentiation the question is:
y^2 + x/y + 4x^2  3 Stephen La Rocque lui répond. 





Log base 2 of log base 2 of x 
20070627 

alex pose la question : y = log base 2 of lag base 2 of x
The slope of the tangent to the given curve at its xintercept is..? Harley Weston lui répond. 





The third derivative 
20041015 

Holly pose la question : Why would you ever take the third derivative? Harley Weston lui répond. 





Differentiation 
20040804 

A parent pose la question : I am a parent trying to understand higher level of maths and would be very grateful if you could help with differentiating the following functions, identifying general rules of calculus:
a) f(x)=e^2^xIn(cos(8x))
b) f(x)=secx/SQRTx^4+1 Penny Nom lui répond. 





Areas, perimeters and derivatives 
20040215 

Geoff pose la question : A recent lecture in my calculus class led me to realize that the derivative of the area of a circle, with respect to the radius is equal to the circumfrence. This also holds true for the relationship between the volume of a sphere and the surface area of that sphere:
why do these hold true? why is it only for circular objects? Harley Weston lui répond. 





Functions, graphs and derivatives 
20031005 

Jathiyah pose la question : I wanted to know how would you tell (on a graph diplaying two funtions), which funtion is the derivative of the other? Walter Whiteley lui répond. 





Derivatives, there must be an easier way 
20000906 

Brad Goorman pose la question : The direction read: Take the derivative of each expression. y = {1+[x+(x^{2} +x^{3})^{4}]^{5}}^{6}
Harley Weston lui répond. 





Mathematical Induction and the Derivative 
19970318 

Shuling Chong pose la question : "Obtain a formula for the nth derivative of the product of two functions, and prove the formula by induction on n." Any educated tries are appreciated. Penny Nom lui répond. 

