How do i find inv for sin,i have tried the mode Deg 1 but i keep getting the wrong answer. can you help? Eg 0.6339869 INV cos ans should be 50.655113.

To get the inverse trigonometric functions press the 2nd key then the trig function key. If you'll look at the key legends above the SIN, COS, and TAN keys you'll see the standard math notations for their inverse function.

The INV key that you may find on some scientific calculators has, on the TI 83/84/ Plus calculators, an equivalent key marked [2nd].

On the TI83/84 Plus, each trigonometric function has a second marking [SIN^-1], [COS^-1] or [TAN^-1]. To calculate the inverses of trigonometric functions ( arc sine, arc cosine, arc tangent) you press [2nd] followed by the relevant trigonometric function key For example, [2nd] [SIN] displays sin^-1( on the command line.

Unfortunately the hyperbolic functions and their inverses are only accessed through the CATALOG. You press [2nd][0] to open the CATALOG. Then you scroll down the CATALOG list to reach cosh(, cosh^-(, sinh(, sinh^-1(, tanh(, or tanh^-1(.
To speed the search in the catalog, you use the ALPHA keyboard: To reach cosh(, press[PRGM] and you scroll down from there.

Let's start with a little background.

The cot(x) is also known as the cotangent(x) and it equals 1/tan(x) which equals cos(x)/sin(x). I'm showing these formulas because your calculator may not have a cot button but it will probably have buttons for tan, cos, and sin.

Your calculator may also have buttons for tan-1, cos-1 and sin-1. These are the inverse functions for tan, cos, and sin. If you enter a number and then push the tan-1 button, the result is the angle whose tangent is the entered number. For example, it you enter 1 and push the tan-1 button the answer will be 45 deg because tan (45 deg) = 1.

Now let's look at the problem, cot(x) = -0.6.
The first thing we need to know is do you want the answer in degrees or radians? Your calculator will have both modes. The default mode when you first turn it on is probably degrees. If this problem is in radians you will need to change the mode of your calculator over to radians before we start.

If cot(x) = -0.6, then tan(x) = 1/-0.6 from the formula I showed in the background section.

This means tan(x) = -1.6666666...

Now we just enter -1.66666667 and hit the tan-1 button to get the answer.

If we're operating in radians the answer is -1.0307 radians.
If we're operating in degrees the answer is -59.036 deg.

I hope this helps you out.

Make sure the argument is between negative one and positive one, inclusive. The inverse cosine is defined only for arguments in that domain, anything else will give you a domain error.

Of course. Just press the INV key before pressing the appropriate trig function key. For example, to calculate the inverse sine, press INV then sin.

I depends on what you mean by INV.
On some Chinese (AUREX, Staples) calculators the second function key is marked as INV. If that is the key you have in mind, on Casios it is the [SHIFT] key. On Sharps it is marked as [2ndF]

If you have in mind the multiplicative inverse (the reciprocal) then your calculator has such a key and it is marked [x^-1]. It the key represented on the following table at the intersection of the 2nd column and the 9th line (RECIPROCAL)



If you are thinking about the inverse of functions, then know that each function shares the same physical key as its inverse. For example to access the arcsine (the function inverse of sine) you press the [SHIFT] key before [SIN]. On the calculator you will notice that near the [SIN] key and to its left there is [SIN^-1].

Hello,
1.Set the correct angle unit required by your problem: degrees, radians, or grads. [SHIFT][MODE] [3:deg] or [4:Rad]

2. Press the key for the function COS, SIN, or TAN
[COS] displays Cos(

3.Enter the angle 12 deg Screen shows cos(12
Close the right parenthesis ) Screen shows cos(12)
4.Press [=] Screen displays 0.9781

If you want the inverse trigonometric functions you access them with arccos [SHIFT] [COS] (cos^-1)
arcsin [SHIFT][SIN] (sin^-1)
actan [SHIFT][TAN] (tan^-1)

You have to know the principal domain for the inverse trigonometric functions (see any book on trigonometry) to understand the results.
Hope it helps.

Try the 2ND key instead of INV.

There is an inverse button below the math button, but if you hit second and the tan it should give you the inverse of tan. Hope this is what you wanted

here are the steps in changing it from radian to degrees
1. turn on your TI-83 plus
2. press the MODE button near the top of your calculator
3.go down to options and move the highlight from radian to degree, press enter and clear
you're good to go