HP HP-28S - Page 120

~ tan (x
2
+ 1)
dx
d tan (x
2
+ 1) x ~ (x
2
+ 1)
d(x
2
+ 1) dx
The derivative of the tangent function has been evaluated. Next you'll
evaluate
the derivative of x
2
+ 1.
Evaluate the expression a second time.
2:
1 : I ( 1 +SQ <TAN (X"'2+ 1) ) >*
~X(X"'2) I
RI3lr:m::J DB mmilDCIIIlillCI
The result reflects the derivative of a sum:
~ (x
2
+ 1) = ~ x
2
+ ~ 1
dx dx dx
The derivative of 1 is 0, so that term disappears. Next you'll evaluate
the derivative of x
2
.
Evaluate the expression a third time.
I EVAL I 1'::2:-:':-----------,
1 : I ( 1 +SQ <TAN (X"'2+ 1) ) >*
(~X(X)*2*XA(2-1»'
RI3lr:m::J DB mmilDCIIIlillCI
The result again reflects the chain rule:
~ x
2
= ~ (X)2 X ~ x
dx dx dx
The derivative of x
2
has been evaluated. Finally, evaluate the deriva-
tive
of x itself.
Evaluate
the expression a fourth time.
I EVALI ~2~:-----------,
1 : I ( 1 +SQ <TAN (X
A
2+ 1) » *
(2*X) I
RI3lr:m::JDBmmilDCIIIlillCI
Here is the fully evaluated derivative.
10: Calculus 119