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CS13486
Scientific Calculator (FX-991ESPLUS)
Casio Fx-991es Scientific ...
CASIO4.93548331Scientific Calculator FX-991ESPLUS

CASIO

Scientific Calculator (FX-991ESPLUS)

BCD40
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Specifications
Batteries
1 LR44 batteries required. (included)
Color
white
General
Brand
CASIO
MSRP
BCD40
Description

Casio Fx-991es Scientific Calculator

  • Casio Fx-991es Scientific Calculator
Customer Reviews
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Top Reviews
Good Calculator
by Valued Customer on August 12, 2018
 
 
 
 
 
Verified Purchase

Really nice to double check derivatives and integrals with limits. Also good to use during tests to see where asymptotes are approaching

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A Test of the Speediness in Numerical Integration for Four Calculators
by Valued Customer on July 12, 2018
 
 
 
 
 
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The four calculators are:1. The TI-36X Pro (scientific calculator)2. The Casio fx-115ES Plus (scientific calculator)3. The Casio fx-991EX ClassWiz (scientific calculator)4. The Casio fx-9750gii (graphing calculator)The problem used for test:B = 1.3271244e+20C = 6.957e+08D = 1.495978707e+11Evaluate:�� (C, 0.999999D) 1 / ��(2B(1/x �� 1/D)) dxThis integral returns the amount of time, in seconds, for an object to fall to the sun's photosphere (one solar radius = C) starting from a distance of 1 astronomical unit (D), assuming that the sun and the object are initially at rest with respect to each other and are acted upon by no forces other than their mutual gravitational attraction. The variable B is the solar gravitational parameter.TI-36X ProAnswer: 5570898.581Time to Solve: 90.4 secCasio fx-115ES Plus � this calculator is being reviewed (almost identical to the fx-991es plus)Answer: 5570898.583Time to Solve: 76.6 secCasio fx-991EX ClassWizAnswer: 5570898.583Time to Solve: 17.3 secCasio fx-9750giiAnswer: 5570898.583Time to Solve: 4.9 secAs you can see, the Texas Instruments device is a slow-poke. The TI-36X Pro costs anywhere from $19 to $30 on Amazon.The Casio fx-991EX ClassWiz is the official (and substantial) Casio upgrade to the earlier Casio fx-115ES Plus. For moderately complicated numerical integration chores, the Casio fx-991EX is more than four times faster than its predecessor model. Furthermore, the Casio fx-991EX is more than five times faster than its ostensible competitor from Texas Instruments, the TI-36X Pro. The Casio fx-991EX sells at prices ranging from $14 to $36 on Amazon.But the Casio fx-9750gii is more than three times faster than the Casio fx-991EX ClassWiz and is about 18 times faster than the TI-36X Pro. Reasonable prices on Amazon go from $30 to $37, but there are some sellers (that should be ignored) who are trying to gouge for more.I have solved the indefinite integral analytically. Omitting the intermediate steps,�� 1 / ��(2B(1/x �� 1/D)) dx= ��[D/(2B)] { ��(XD��X?) + D arctan[��(D/X��1)] }When I used the calculators to solve the integral numerically, I had to avoid entering D itself for x, since that would cause an overflow error. But in the analytical solution, when X=C, the answer is 5578001.670517. When X=0.999999D, the answer is 7103.088517. So the precise answer from the analytical solution, used twice to evaluate the integral from X=C to X=0.999999D, is 5570898.582. There is no appreciable error in the numerical results from any of the calculators.

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Five Stars
by Valued Customer on July 05, 2018
 
 
 
 
 
Verified Purchase

good

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Excellent calculator
by Valued Customer on June 22, 2018
 
 
 
 
 
Verified Purchase

Fantastic calculator. Nice simple interface. Shipment came right in time. Thank you!

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It All Adds Up
by Valued Customer on June 10, 2018
 
 
 
 
 
Verified Purchase

Does the job

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Five Stars
by Valued Customer on May 31, 2018
 
 
 
 
 
Verified Purchase

nice

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Five Stars
by Valued Customer on April 15, 2018
 
 
 
 
 
Verified Purchase

Works well

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Best calculator I've ever owned!
by Valued Customer on April 11, 2018
 
 
 
 
 
Verified Purchase

Could solve integrals that online solvers couldn't :)

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Five Stars
by Valued Customer on March 14, 2018
 
 
 
 
 
Verified Purchase

Very good. It can solve equation.

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Very good
by Valued Customer on March 04, 2018
 
 
 
 
 
Verified Purchase

Brand new calculator as i expected.

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Five Stars
by Valued Customer on March 03, 2018
 
 
 
 
 
Verified Purchase

Amazing

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its kindha complicated to use at first but once understood its really easy to use
by Valued Customer on February 23, 2018
 
 
 
 
 
Verified Purchase

Durable. its kindha complicated to use at first but once understood its really easy to use. Way better than using excel hahaaa!

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