__Frequently Asked Questions__

This section is currently under construction.

__Basics of Calculator Operation__

__1.__ How do I make the home screen darker on the TI83?

__2.__ How do I make the home screen lighter on the TI83?

__3.__ What would be an example of roundoff error?

__4.__ How can I clear a drawing from the graph screen?

__5.__ When I plot the graph of tan(x) in the standard window, why does no graph appear?

__6.__ Why does the calculator say "Error" when I enter the expression (-2-3)?

__7.__ When I turn on the calculator, I do not see a blinking cursor, and the screen is blank. Are the batteries dead?

__8.__ I reset the memory, and now the screen is blank. Did I damage the calculator?

__9.__ How can I find the 14 significant digits of a stored number?

__10.__ How do I enter the variable Y_{1} onto the home screen?

__11.__ I put new batteries into my calculator, and now the screen is completely dark. What happened?

__12.__ I just typed in a complicated expression and realized I made a mistake. Do I have to retype the whole thing again?

__13.__ I was working on a group of computations about 5 minutes ago and now I want to look at them again. Is there any way to get them back?

__14.__ I know that 9^(3/2) =27, but when I do it on the calculator, I don't get that answer. Why?

__15.__ I type x^2+1 on the home screen and then press enter and I get the number 26, my neighbor does the same and gets the answer 1. Why are we getting answers here if we haven't keyed in any values for x?

__16.__ How can I clear the memory of the TI83?

__17.__ I have a program in my TI83 entitled "APROGRAM". How can I delete "APROGRAM" without deleting anything else?

__18.__ How can I transmit information from one TI-83 calculator to another TI-83 calculator using the "communication link"?

__Functions__

__1.__ How do I set up a function in the TI83?

__2.__ How do I create a table of numbers using the Y_{1} function?

__3.__ How can I see more decimal places for the numbers in a table?

__4.__ How can I delete the numbers in a table?

__5.__ How can I set up the cube root function?

__6.__ How can I graph a function that is in the Y_{1} function variable?

__7.__ How can I set up a piecewise function?

__8.__ When I try to graph I get error "dimension". What does this mean?

__9.__ How can I graph a family of curves, such as x^{2} + 3 y^{2} = C, for C = 1,4,9 ?

__10.__ How can I set up a table of function values on the TI85 calculator?

__11.__ When I plot the function (X^2) * Cos(20 Pi X) in the decimal window, why do I get a parabola?

__12.__ Can you give me some pointers on how to set up a good window to view a graph?

__13.__ How can I find the solution to the equation f(X) = 0 ?

__14.__ In order to zoom in on a graph, I moved the graph cursor to a point near my function graph. I then zoomed in, and the graph disappeared completely. What happened?

__15.__ How can I zoom in on a graph of a function?

__16.__ How can I compute a) cot ^{-1}(x) , b) sec ^{-1}(x) , and c) csc ^{-1}(x) using the TI-83 calculator?

__Limits__

__1.__ How can I guess the value of a limit of a function as x approaches "a" using the calculator?

__2.__ I'm trying to compute limit as x approaches zero of (1+x)^(1/x) but keep getting infinity. I know I am supposed to get e. What is going on?

__Derivatives__

__1.__ How can I evaluate the numerical derivative of f(X) at the point x=a using the calculator?

__2.__ I know that y=abs(x) is not differentiable at zero, but when I try to find the numerical derivative at 0, instead of the calculator telling me it doesn't exist, it gives me zero. Why?

__3.__ When I try to compute the numerical derivative of y=1/x at zero, I am getting a finite number? How could that be?

__4.__ I have a formula for the function f(x). I used the derivative laws to get a formula for f '(x). How can I check my formula for f '(x) using a TI83 calculator?

__5.__ I have an equation in the form f(X,Z) = 0. I used implicit differentiation to get a formula for dZ/dX. (The formula for dZ/dX is an expression in Z and X.) How can I check my formula for dZ/dX using a TI83 calculator?

__Curve Sketching__

__1.__ How can I find the coordinates of inflection points with the calculator? I try tracing but don't really know if I am on or near the inflection point.

__2.__ I try graphing y=(x^2-1)/(x-1) . The teacher says I should get something that looks like a line but I don't. What am I doing wrong?

__3.__ My screen shows that my two graphs intersect in two points, but each time I try to calculate the intersection, I always get the first intersection point. Why can't I get the second intersection point?

__4.__ How do I stop the machine from graphing while it is graphing?

__5.__ I am in the standard window and want to get the cursor to the point on the curve where x=9. So I press trace and then the right arrow button a million times. Isn't there a faster way to get there?

__6.__ I entered the expression (X^2)*(Y^3) into the Y_{1} function variable. I then went to the home screen and stored the number 2 into Y. Next, I pressed [GRAPH], expecting to get the graph of 8*(X^2). Instead, I got the message "ERROR: INVALID". What happened?

__Integration__

__1.__ How can I form a Riemann sum on a regular partition using the calculator?

__2.__ How can I evaluate the (numerical) definite integral of f(X) from "a" to "b" using the calculator?

__3.__ Is there a program that will show me the rectangles that are being used when computing a Riemann sum?

__4.__ I have a formula for the function f(x). I use theorems to get a formula for F(x), an antiderivative (or integral) of f(x). How can I check my formula for F(x) using a TI83 calculator?

__5.__ I have a formula for f(x). However, I do not have a formula for an antiderivative of f(x). How can I use the TI83 calculator to generate a graph of an antiderivative of f(x)?

__6.__ How can I approximate a definite integral with a TI83 using the midpoint rule, the trapezoid rule, and Simpson's rule?

__Inverse Functions__

__1.__ How can I plot the graphs of y=f(x), y=f ^{-1}(x), and y=x on the same set of axes?

__Parametric Equations__

1. How do I graph a function of y?

__2.__ How do I find the intersection of curves when the graphs are done in parametric mode?

__Polar Equations__

__Sequences and Series__

__1.__ How can I find the partial sums of a series on the calculator?

__2.__ Suppose I know that a power series c_{0} + c_{1}*x + c_{2}*x^{2} + ... + c_{n}*x^{n} + ... converges to f(x) in the interval -R < x < R (where an expression for f(x) is known). How can I graph f(x) together with the first several partial sums s_{n}(x)?

__3.__ How can I use the sequence mode functions u, v or w to generate a sequence, and then store the sequence in a list variable?

__4.__ How can I use the "seq" instruction (in the LIST OPS menu) to generate a sequence, and then store the sequence in a list variable?

__5.__ How can I "manually" create a list of numbers and store the list in a list variable?

__6.__ How can I plot the five data points (4,2), (-3,4), (2,2), (-2,-1), (1,3) on the graph screen?

__7.__ How can I plot the graph of a sequence of numbers?

__8.__ How can I simultaneously graph the terms of a series and the terms of the corresponding partial sum sequence?

__Vectors and Matrices__

__Functions of Several Variables__

__Multiple Integrals__

1. How can I use the TI83 calculator to evaluate the Riemann sum for a double integral over a rectangle R, using a regular partition, and using midpoints in the subrectangles?

__Applications__

__1.__ Einstein's Approximation for Heat Capacity

__2.__ A Descriptive Model of Signal Propagation on an Unmyelinated Neural Axon

__3.__ Electric Fields Generated by Stationary Point Charges

__4.__ Steady State Groundwater Flow in a Rectangular Region

__Programs for the TI83__

__1.__ My TI83 program will not stop running. It appears to be caught in an "infinite loop". How can I interrupt the execution of the program?

__Problems Where the Calculator Gives an Incorrect Answer__

__Methods for Using the Calculator to Present Calculus Topics__

__Resources for Calculus Projects__

__Links to Other Calculus Sites__

__Reviews of Calculus Books, Web Sites, Etc__

__Calculus Forums__

__References to Articles on the Use of the Calculator in Calculus Courses__

__Q____uestions to be Answered__

(Answer to appear) **1.** If the calculator can get limits for me, why do I have to bother with limit techniques?

(Answer to appear) **2.** How can I graph the sum function of a power series (in its interval of convergence)?

(Answer to appear) **3.** How does one graph the limit function of a convergent sequence of functions?

__Back to main menu__

Section links:

__Frequently Asked Questions__

__Basics of Calculator Operation__

__Functions__

__Limits__

__Derivatives__

__Curve Sketching__

__Integration__

__Inverse Functions__

__Parametric Equations__

Polar Equations

__Sequences and Series__

__Vectors and Matrices__

__Functions of Several Variables__

__Multiple Integrals__

__Applications__

__Programs for the TI83__

__Problems Where the Calculator Gives an Incorrect Answer__

Methods for Using the Calculator to Present Calculus Topics

Resources for Calculus Projects

Links to Other Calculus Sites

Reviews of Calculus Books, Web Sites, Etc

Calculus Forums

References to Articles on the Use of the Calculator in Calculus Courses

__Final Examinations__