CPhill

Be careful here......this is a common mistake to assume that -5^2 = 25......!!!!

-5^2  = -1(5)(5) = -25      the exponent only applies to the 5, NOT  to the "understood" -1 preceding 5

However......

(-5)^2 =  (-5) (-5)  = (-1 * 5) (-1* 5)  = (-1 * -1) (5 * 5)  =  (1) (25)  = 25

 See the difference???

Absolute value is just the distance between a particular number and 0 on the number line....

So... abs(pi)  =  l pi l   = pi   ..... since it's "pi" units from 0...!!!

Don't get confused here, MG1.....

1! + 2! + 3! + ..... + 1393!  is a shorthand notation for summing  all the integer factorials from 1 to 1393.....{there are 1393 terms to be summed !!}

I don't know what this sum might be, because 1393! by itself would "wreck" our calculator....{the sum is not infinity, however......but definitely a HUGE number.... }

Well....if you're referring to math, maybe we can help......post your question(s)......

Nice answer, Mathcad....!!!

Example  

x^2  - 10x  + 25 =  0

x = [ -b ± √[b^2  - 4ac ]  / [2a]

x = [ 10 ± √[(-10)^2  - 4(1)(25)] / [2(1)] =

x = [10  ± √[100 - 100] / 2 =

x = 10 / 2  =  5

Pi is irrational....which means that its value isn't precisely determined.....however......we can use 3.14 for most practical purposes.....

C = pi * d    ....so...

15 cm  = pi * d    divide both sides by pi

(15/ pi) cm = d = about 4.77 cm

We have......

 691.12 ft / 21.2 s    =   means the object moves 32.6 ft in 1 second

And

21.2s / 691.12 ft  = means the object moves 1 foot in about .030 seconds

BTW...nice animated gif ....!!!!

Welcome aboard.....!!!!!

I'll even give you 3 "complimentary" points to get you started...!!!