how to use tan function in micosoft works spreadsheet

[philrainey]

1. The problem statement, all variables and given/known data
IN microsoft works spread sheet how do you insert a inverse tan function. that is I know the opposite and adjacent side lengths but want to use the tan function to find the angle of a right angle triangle.Please help ,simple I know but I just can't work out how to do it. Does microsoft works work in degrees rads or grad by default?


2. Relevant equations



3. The attempt at a solution

[mgb_phys]

If it's the same as all the other versions of excel then it is "asin(x)"
the result is returned in radians, you can etiher use degress(asin(x)) or simply multiply by 57.3

[Phrak]

=DEGREES(ATAN2(x,y)) will return an angle in any quadrant

Experimenting, I find that the return value, theta ranges as -180 < theta <= 180.

[mgb_phys]

One thing to be careful of, excel's atan2() function has the arguements in the opposite order to most libraries which are atan2(y,x), since atan2(y,x) = atan(y/x)

[philrainey]

Yes thankyou it works in radians. I was trying to work out a question where there is a little sphere inside a big sphere with a perfect vaccuum inbetween.the big sphere been 0.13m dia. and 1550 degrees kelvin hot. The little sphere .1m dia. and 1500 degrees kelvin. All of the radiation from the little sphere hits the big but some from the big misses the small and hits itself.What is the net radiation between them ?