Top 20 Texas Instruments TI-84 Plus Calculator - Page 5 Questions & Answers

Press f followed by a digit representing the number of digits you want after the decimal point.

On the x-axis (horizontal axis) represent the time variable. On the y-axis (vertical axis) represent the temperature.

Question?

x^2+13x+15=0 Recall (x+a)^2=x^2+2ax+a^2 Write x^2+2*(13/2)x+15, and compare the terms in x. a=13/2 x^2+13x+15=x^2+2(13/2)x+(13/2)^2-(13/2)^2+15 The first three terms are the expansion of (x+13/2)^2 You expression is equivalent to (x+13/2)^2-[(13/2)^2-15]=(x+13/2)^2-[SQRT(109)/2]^2 Use the identity for the difference of two squares a^2-b^2=(a-b)(a+b) This gives x^2+13x+15=(x+13/2)^2-[SQRT(109)/2]^2= [x+13/2 -SQRT(109)/2][x+13/2+SQRT(109)/2] The polynomial can be written as (x-a)(x-b) (Note a has nothing to do with the one used above to complete the square. You can use any name for the roots, x_1, x_2, anything. The two roots are on the screen captures below. PS. I prefer to manipulate exact expressions with radicals. If you do not like it use the decimal approximations.

See captured image below

To graph a sequence, you must set the Graph Mode to Seq. On line Func, use the right arrow to highlight Seq. this way when you press the key X, T, Theta, n you enter the variable n Make sure you turn off the StatPlots. Press [2nd][Y] (StatPlot), then select [4:PlotsOff]. See the screen capture.

TI calculators have an annoying habit of dimming the screen when the batteries are changed so that it appears as if the calculator isn't turning on. Turn the calculator on (or at least press the ON key). Press and release the 2ND key. Press and hold the Up-arrow key for a few seconds and see whether the screen becomes legible.

remove the battery and insert.

Press LOG 3 ENTER

The arccosine function is defined for arguments in the range -1 to +1. -125.85/-120.36 is larger than 1 and hence outside the domain of the arccosine function.

If you have the latest OS, press the ALPHA key then use the F1 and select 2 Un/d

If you backed up the calculator, you may be able to restore lost data. Failing that, there is nothing you can do.

No. The graph of a circle is a graph, one which can have two different values for certain arguments. The graph of the top or bottom half of a circle can be considered a graph of a function.

Play with the display contrast to darken it. Press 2nd key and release it Press UpArrow and hold pressure until you get something on screen. Up and Down Arrow keys allow the control of the contrast.

When the radicand is completed, use the right arrow to leave the root so that you can enter the other factors or terms.

You're probably trying to graph a function that does not involve stat plot features. You can correct this by turning off the stat plot features. Press "2ND" "STAT PLOT" and then select 4:PlotsOff. If you're doing something else, what exactly?

TI calculators have an annoying habit of dimming the screen when the batteries are changed so that it appears as if the calculator isn't turning on. Turn the calculator on (or at least press the ON key). Press and release the 2ND key. Press and hold the Up-arrow key for a few seconds and see whether the screen becomes legible.

Type: ln(3)/(2ln(3)-ln(5)) See captured image below