Look for this session in /home/ceng303/maple/sessions as: ch1_7.mw

Session 1.7: Differentiating expressions and functions with diff

> restart;

>fe1:=x^2; Expression giving the square of x

>fe2:=x*sin(x)-x; More complicated Expression

>dfe1:=diff(fe1,x); Derivative of fe1 with respect to x

>dfe2:=diff(fe2,x); Derivative of fe2 with respect to x

>f1:=x->x^2; Function giving the square operation

>f2:=x->x*sin(x)-x; Second function

>df1:=diff(f1(x),x); Note : you must specify f1 as a function of x

>df2:=x->diff(f2(x),x); Here is another way to produce a function

Higher order derivatives may also be produced

> fe3:=(x^2+y^2)*sin(x)*cos(y); An expression that depends on x and y

>diff(fe3,x); The derivative of fe3 with respect to x

>diff(fe3,x,y); The second partial derivative (wrt x and y)

> f3:=(x,y)->(x^2+y^2)*sin(x)*cos(y);The arrow form of a function that gives the same result as fe3.  The order of variables is significant.

>diff(f3(u,v),u); Change variables from (x,y) to (u,v)

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