SOLUTION: I would like some help. my book says I can type this into my calculator but when I try to put it in it says error i type it word for word. If I don't add the 24 with the brackets i

Algebra ->  Trigonometry-basics -> SOLUTION: I would like some help. my book says I can type this into my calculator but when I try to put it in it says error i type it word for word. If I don't add the 24 with the brackets i      Log On


   

Question 716587: I would like some help. my book says I can type this into my calculator but when I try to put it in it says error i type it word for word. If I don't add the 24 with the brackets it works but I don't get the right answer. Please Help!
This is the formula D=24[1-cos^-1(tan i tan theta)/ pie]
approximate the number of hours of daylight in Houston, Texas (29degrees 45' north latitude), for the following dates:
(A) summer solstice(i=23.5 degrees)
(B) Vernal equinox (i=0 degrees)
(C) July 4 (i=22 degrees 48')
Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
Here's a list of things to try:
  1. Most calculators do not have buttons for brackets. See what happens if you replace the brackets with parentheses.
  2. Make sure you have the formula correct, especially the part with the two tan's. (I'm not familiar with this formula but multiplying two tan's seems weird to me.)
  3. Use "*" for any implied multiplications:
    • between the 24 and the first "("
    • Between the two tan's?
  4. Enter the angles as decimal numbers of degrees:
    • 29 degrees 45 (minutes) = 29%2645%2F60 degrees = 29%263%2F4 degrees = 29.75 degrees
    • 22 degrees 48 (minutes) = 22%2648%2F60 degrees = 22%264%2F5 degrees = 22.8 degrees
  5. Make sure use use the button for the inverse cos. Do not use the cos button and then try to raise it to the -1 power.
If none of these help, I'm not sure what might be causing your error