Sam wants to ensure that the tone of his informational e-mail matches his intent. he should a. delete the e-mail and phone the recipient instead b. read the message aloud to himself c. wait 72 hours before sending the message d. include several exclamation points to express enthusiasm

Which of these is a benefit of using objects in a powerpoint presentation? a. collaborators can create the external files while you create and edit the slide show. b. you can easily change the theme and design of the presentation. c. you can have older data in the source file while having up-to-date data in the presentation. d. collaborators can easily share the presentation.

Write a program that prints the day number of the year, given the date in the form month-day-year. for example, if the input is 1-1-2006, the day number is 1; if the input is 12-25-2006, the day number is 359. the program should check for a leap year. a year is a leap year if it is divisible by 4, but not divisible by 100. for example, 1992 and 2008 are divisible by 4, but not by 100. a year that is divisible by 100 is a leap year if it is also divisible by 400. for example, 1600 and 2000 are divisible by 400. however, 1800 is not a leap year because 1800 is not divisible by 400.

For positive constants a and b, the force between two atoms in a molecule is given f(r) = −a r2 + b r3 , where r > 0 is the distance between the atoms. note: a and b are upper case letters. (a) find f '(r) = (b) find the critical point for f(r). r = (c) find f ''(r) = (d) find the value of r so that f ''(r) = 0.