Write the equation in standard form of a circle with center (-4,2). The standard form of the equation for of the circle is what?

Express the following as a function of a single angle, cos(60) cos(-20) - sin(60) sin(-20)

If 2(a^2+b^2)=(a+b)^2 then, > a+b=0, > ab=0, > a=b, > 2a=b

Bob is putting books on a shelf and takes a break after filling 18 1/2 inches on the book shelf. the book shelf is now 2/3 full. how long is the entire bookshelf?