Solve crash

[jebem]

(04-04-2016 07:00 PM)Han Wrote:  

(04-03-2016 10:04 PM)lrdheat Wrote:  Prime calculator freezes and on IPad crashes when solving 48*x*(1+x)^60 -(1+x)^60 +1=0.

TI nSpire, WP 34s, CASIO f'x-9860gii, CASIO fx-991EX CLASSWIZ all solve the problem.

Problem from James Stewart Calculus 6E from 2008 page 334

I did not get a crash on my prime. In fact, it very quickly returned {0} as a solution. Remember that solve() attempts to give exact solutions. If you expect non-exact results, either specify an interval and/or use fsolve() (for floating point).

EDIT: Also, you can find the three roots using the plot app.

Hi, Han,
Same here with my Physical Prime:

Typed in the equation using solve:
solve(48*x*(1+x)^60 -(1+x)^60 +1=0)
in CAS mode and it took about 2 to 3 seconds to return the result {0}.

Trying fsolve returns the results in about the same time:
solve(48*x*(1+x)^60 -(1+x)^60 +1=0)
returns 0

solve(48.*x*(1.+x)^60 -(1.+x)^60. +1.=0)
returns [-0.225800920842 -0.144166796312]

Trying csolve:
This puts the hourglass at the upper right corner for about 50 seconds:
csolve(48*x*(1+x)^60 -(1+x)^60 +1=0)
returns 0

and this returns the result in about 2 seconds:
csolve(48.*x*(1.+x)^60. -(1.+x)^60. +1.=0)
returns a HUGE solution listing in the form {a+b*i, ...} with 60 complex answers and the last the elements are just -0.225800920842, -0144166796312, 0.

I would say this is an impressive result.


My Prime setup is as follows:

About HP prime:
Software version: 2015 6 17 (8151)
Hardwrae Version: A
CAS Version: 1.1.2-11
Operating System: V0.037.526


CAS settings:
angle: degrees
Number format: Standard 12
Integers: Decimal Check
Simplify: Minimum
Exact: check
Complex: No check
Use sqrt: Check
Use i: No check
Principal: Check
Increasing: No check
Recursive Evaluation: 5
Recursive Replacement: 1
Recursive Function: 9
Epsilon: 0.000000000001
Probability: 1e-15
Newton: 40

HOME settings:
Angle measure: Degrees
Number Format: Standard
Digit Grouping: 123456.789
Entry: Textbook
Integers: Hex 32
Complex: a+b*i
Language: English