Find the domain of the following piecewise function.

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

Solve 3x-18=2y and 5x-6y=14 by elimination or substitution . show all !

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 0 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)