My TI-30XB WONT CALCULATE INVERSE COS OR INVERSE SIN

SOURCE: TI-84 Plus silver edition sin/cos/tan

for function = (sin,cos,tan,sec,cosec,cotan)
arc(function) = function^-1, calculated in the first quadrant for simplicity(0-pi/2) (0-90deg), as all functions repeat circularly
just another method of notation

http://www.mathwords.com/t/tangent_inverse.htm

SOURCE: Using Cos/Sin

Calculator turns on in "degree" mode. Just enter angle in degrees then press "SIN", "COS" "TAN".

Most people work in degrees but you can switch to Rads or Grads to Degrees modes by pressing "DRG" repeatedly with zero displayed, Current angular mode will show in display.

Get a new instruction booklet by download from TI website

SOURCE: how do i use the inverse log operation on the TI-84

The problem is simple. You're trying to get an [H+] concentration which is obviously going to have a value of some number times ten raised to a negative power. Therefore, you have to insert the negative value of the pH into the 10^(x). When you insert said negative number you will come out with the right answer.
i.e.
The pH of a sample of human blood was calculated to be 7.41. What is the [H+] concentration of the blood?
10^(-7.41) = [H+]
[H+] = 3.9 E-8  
(the answer should only have two sig. figs because the pH has two digits after the decimal.

SOURCE: How do I calculate the inverse log on the TI-89?

Hello,
The wrong terminology is playing tricks on you.

1. If you are talking about the natural logarithms, the inverse function of the natural log is the exponential: ln(e^(x))=e^(ln(x)) = x
2. If you are talking about the common logarithms (log in base 10) to find the antilog of a number, say x, you raise 10 to the power of x.

SOURCE: Using the correct key combination to determine inverse log

Hi,
Sorry to contradict you but there are many types of logarithms, the most important ones are

1. the common logarithms (log in base 10),
2. the natural logarithms (logarithms in base e)
3. the binary logarithms (logarithms in base 2)