Page 413 - Excel 2013 All-in-One For Dummies

on that rare, rare occasion when you have to raise a number by a fractional power. In that case, you need to use the POWER function instead of the caret (^) operator to get the correct result. For example, suppose that you need to raise 20 by the fraction 3/4; to do this, you build the following formula with the POWER function:
=POWER(20,3/4)
To use the exponentiation operator to calculate the result of raising 20 by the fraction 3/4, you can convert the fraction into decimal form, as in
=20^0.75
The SQRT function on the Math & Trig command button’s drop-down menu enables you to calculate the square root of any number that you specify as its sole number argument. For example, if you use the SQRT function to build the following formula in a cell:
=SQRT(144)
Excel returns 12 to that cell.
The SQRT function can’t deal with negative numbers, so if you try to find the square root of a negative value, Excel returns a nice #NUM! error value to that cell. To avoid such a nuisance, you need to use the ABS (for abso- lute) math function, which returns the absolute value of a number (that is, the number without a sign). For example, suppose that cell A15 contains ($49.00), showing that it’s something you owe, and you want to return the square root of this number in cell A16. To avoid the dreaded #NUM! error, you nest the ABS function inside the SQRT function. The ABS function returns the absolute value of the number you specify as its sole argument (that is, the value without its sign). To nest this function inside the SQRT function, you create the following formula:
=SQRT(ABS(A15))
Excel then returns 7 instead of #NUM! to cell A16 because the ABS function removes the negative sign from the 49.00 before the SQRT function calculates its square root. (Remember that Excel always performs the calculations in the innermost pair of parentheses first.)
The SUM of the parts
No function in the entire galaxy of Excel functions comes anywhere close to the popularity of the SUM function in the spreadsheets that you build. So popular is this function, in fact, that Excel has its own Sum command button
Math & Trig Functions 395
Book III Chapter 5
Math and Statistical Formulas