20. Reverse-Polarity Machining is a new development that promises to be a major breakthrough in reducing electrode wear.

6.  How many sparks per second does the wire produce.

Bonus 1   Which electrode material has less wear when using EDM?    

Solve the problem.A ball is thrown downward from a window in a tall building. Its position at time t in seconds is where s is in feet. How long (to the nearest tenth) will it take the ball to fall 213 feet?

Graph the function.g(x) = -(x + 5)3 + 5

Find the sum or difference. Write the answer in standard form.(7 + 5i) – (-9 + i)

If the function is one-to-one, find its inverse. If not, write “not one-to-one.”f(x) = x3 + 3

Compute and simplify the difference quotient , h ≠ 0.f(x) = 8×2 + 9x +7

Graph the function.f(x) = |x| + 2

Give all solutions of the nonlinear system of equations, including those with nonreal complex components.x2 + y2 = 41x + y = -9