# TI 84

## Know your TI 84 GDC

### 1 GDC set up and preapring for exams

This is about making sure you have all the right settings in place (degrees and derivative) and have your GDC set up for exams. A couple of small things that can make a bug difference

### 2 Entering functions

This is a really important feature that makes life a lot easier and is at the heart of why you are allowed this tool. Know how to enter and plot different functions.

### 3 The viewing window

Often overlooked, it can be frustrating if you don't know how to do this. Know how to change the viewing window and zoom so that you can see the parts of a function you want to deal with.

### 4 The table function

So useful in so many ways! So often we are looking to find y values that correspond with different x values and vice versa. Know how to set and use this table function so you can profit from it!

### 5 Finding key points

Find roots/zeros/x-intercepts, max/min, intersections and more. The 'calc' button is brilliant!

### 6 Calculus

Find the gradient of a function at a given point and the equations of tangents and normals.

### 7 Using lists and 1 variable data analysis

These questions are not often worth a lot of marks because you are supposed to get your GDC to do the work.  Know how to enter lists and process one varibale data to get mean, standard deviation, median and quartiles.

### 8 Frequency tables and 1 variable analysis

DONT miss this! When you have a frequency table then your GDC needs to know the second list is a frequency. You have to tell it when it is and isn't. This is so often missed. This is still 1 variable data, but just a question of entering efficiently and setting up the GDC to work with it propoerly.

### 9 Bivariate data and Linear regression

Easy marks when you know how! Use the lists, 2var and regression functions to get correlation coefficient, regression line and mean/standard deviation for both sets of data.

### 10 Chi Squared independence tests

Enter observed frequencies (contingency table) as a matrix to perform a 2 way Chi squared test of independence.

### 11 Normal distribution calculations

• Know how to use the Normal CDF function - Upper and lower limits, mean, standard deviation to determine the probability of a data item being in those boundaries.
• Know how to use the Inverse normal function - Work backwards from the probability (Area), mean and standard deviation to work out the limits that correspond to that probability.

### 12 Equation solvers

Solve linear, quadratic, simultaneous and other equations on your GDC. Its quick and correct and saves lots of time. Know how to use these functions.

### 13 The Finance app

Know how to solve compound interest problems using the finance app and make sure you know how to get the app to do the same thing the formula does.