Tricky(?) Crocodile Maths Exam Question

[Thomas Klemm]

(10-10-2015 06:02 AM)Dieter Wrote:  Let alone with a graphing calculator (enter equation, determine minimum) where the required time essentially depends on how fast you can type. ;-)

Who needs a graphing calculator when you have a HP-15C?

Program for T(x)

Code:

LBL A
ENTER
ENTER
ENTER
X^2
3
6
+
SQRT
5
*
2
0
R^
-
4
*
+
RTN

Solutions to (a)

(i) crocodile does not travel on land
20
A
104.40307

(ii) crocodile swims the shortest distance possible
0
A
110.00000


Program for T'(x)

Code:

LBL B
RCL 0
I
GSB A
Re<>Im
CF 8
RCL/ 0
RTN

Initialisation
EEX
5
CHS
STO 0


Solutions to (b)

x which minimises the time taken
0 ENTER
20
SOLVE B
8.00000

minimum possible time
A
98.00000

Cheers
Thomas