## Factoring Polynomials on the TI-89 and Voyage 200

The TI-89, TI-92 Plus, and Voyage 200 offer two built-in functions for easily factoring expressions and trinomials/polynomials into their component parts. This tutorial explains when to use these functions and how to use them to solve simple equations and polynomials.

## SAT Test Prep #2: Power Rules of Exponents

While you will be able to use a graphing calculator on the SAT, sometimes it is faster to have mathematical rules memorized beforehand so you can quickly solve problems without trying to find the answer by trial and error with your calculator. One type of problem you may encounter on the SAT involves exponents and powers ( for example, (32)4 ).

In this post, we present some easy to remember rules for solving exponents and radicals. By memorizing these rules for simplifying any exponent or radical problem you encounter, you’ll save yourself valuable time while taking the SAT. Keep reading to learn how to add, subtract, multiply and divide exponents and radicals.

## How to Create a Simple Quadratic Formula Program on the TI-89 and Voyage 200

Like the TI-83 Plus and TI-84 Plus, the TI-89, TI-92 Plus, and Voyage 200 graphing calculators all have their own integrated programming language, TI-BASIC. While this language is somewhat more complex on the TI-89/V200 series than the the TI-83 Plus and TI-84 Plus, it offers expanded functionality and is able to take advantage of the TI-89 and Voyage 200′s symbolic math capabilities. This tutorial, like our tutorial for the TI-83 Plus and TI-84 Plus, provides an introduction on how to create a simple program to solve the quadratic formula, which finds the zeros of a quadratic equation.

## Quick Tip: How to Clear Variables on the TI-89, TI-92 Plus, and Voyage 200

Sometimes, it is useful to store specific values in the letter variables (a-z) on your device, especially if you will be using that specific value over and over again. For example, you can store the value of Planck’s constant on your graphing calculator’s button (the same as the the button) by typing 6.626*10^-34 ALPHA . However, later you may want to clear out the variable you created so that letter can again function as a variable. For instance, if you want to use h in the equation for the area of a box, a = l*h, you wouldn’t want to use the value of Planck’s Constant every time you referenced h. To change the value of the variable stored on the key, you need to clear the variable. This article discusses the two ways to accomplish this, either by clearing individual variables or resetting all variables at once.

Filed under Difficulty: Easy, TI-89, TI-92 Plus, Voyage 200 | 1 Comment

## Hypothesis Testing using the Z-Test on the TI-83 Plus, TI-84 Plus, TI-89, and Voyage 200

The TI-83 Plus and TI-84 Plus are optimized for performing many tasks in statistics, and one of their most powerful features is the ability to perform a variety of tests of statistical significance. With the statistics package installed, the TI-89, TI-92 Plus, and Voyage 200 also have much of this capability. This tutorial demonstrates how to use your graphing calculator to solve basic hypothesis testing problems such as the following using the Z-Test:

A researcher designs an experiment where a random sample of n = 50 high school seniors are given a pill to improve their concentration and problem solving skills. After being administered the pill, subjects take the SAT, and their scores on the SAT Math section are tabulated. The average score of student who took the pill is x̄ = 540. Given that the average score of all high school seniors on the SAT is μ = 510 with standard deviation σ = 100, is there statistically significant evidence that students who took the pill scored higher?

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## Business and Finance Math #3: Converting Effective Interest Rates (EAR) to Stated Interest Rates

In our previous blog post we introduced the concept of the effective annual rate (EAR), which is the true interest rate when compounding occurs more than one time per year. For example, 10% compounded semiannually is the same thing as 5% paid every 6 months, representing an annual interest rate of 10.25% per year.

This is an important concept to understand since the quoted interest rate may not be the interest rate you actually earn on your bank account (or pay on your credit card, car payment, or mortgage). While we converted a set of interest rates to the effective annual rate in our previous example to “standardize” the rates, this time we’re going to show you how to do the reverse process on your calculator: converting the EAR to a quoted rate.

## Evaluating Limits on the TI-89, TI-92 Plus, and Voyage 200

The limit of a function is a fundamental calculus concept which is used in characterizing functions, calculating derivatives, and more. This tutorial discusses the theory of limits and how to evaluate limits, including left and right-handed limits, on your TI-89, TI-92, or Voyage 200 calculator.

## Business and Finance Math #2: Calculating the Effective Annual Rate (EAR) on Your TI BA II Plus or HP 12c

Consider the following problem:

Timmy Burns plans to open a new bank account and calls several banks to find out where he can earn the most interest on his money. After talking with several banks, Timmy has three options. Which bank account should he choose to earn the highest return on his money?
8% compounded daily
8.25% compounded quarterly
8.4% compounded annually

It’s not immediately obvious looking at these options which bank account Timmy should choose. At first glance, 8.4% compounded yearly seems to be the highest rate, but is it necessarily the best choice? Read on to learn about the mathematical theory to solve this problem, or skip down to see how you can quickly find the answer with your financial calculator.

Filed under Difficulty: Easy, Finance, HP 12c, TI BA II Plus | 2 Comments

## SAT Test Prep #1: Mean, Mode, and Median on the TI-83 Plus, TI-84 Plus, and TI-89

The following is a sample SAT problem similar to many found on the actual exam:

 Mon Tue Wed Thu Fri Sat Sun 32 28 28 26 21 22 25

The table above shows the temperatures, in degrees Fahrenheit, in a city in Alaska over a one-week period. If m represents the median temperature, f represents the temperature that occurs most often, and a represents the average (arithmetic mean) of the seven temperatures, which of the following is the correct order of m, f, and a?
(A) a < m < f
(B) a < f < m
(C) a = m < f
(D) m < f < a
(E) m < a < f

This tutorial shows how to solve this problem and then how to use your TI-83 Plus, TI-84 Plus, or TI-89 to simplify the process.

Filed under Difficulty: Easy, SAT, Statistics, Test Prep, TI-83 Plus, TI-84 Plus, TI-89 | 5 Comments

## Calculating Derivatives on the TI-83 Plus, TI-84 Plus, TI-89, TI-92 Plus, and Voyage 200

Derivatives are perhaps the most elementary topic in calculus and show up in practically every discipline, from the natural and social sciences to economics and finance. This tutorial discusses the mathematical background of derivatives and demonstrates how to evaluate derivatives on the TI-83 Plus, TI-84 Plus, TI-89, TI-92 Plus, and Voyage 200.

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