91Ó°ÊÓ

ARCHERY An arrow is shot upward with a velocity of 64 feet per second. Ignoring the height of the archer, how long after the arrow is released does it hit the ground? Use the formula \(h(t)=v_{0} t-16 t^{2}\) where \(h(t)\) is the height of an object in feet, \(v_{0}\) is the object's initial velocity in feet per second, and \(t\) is the time in seconds.

Solve each equation by completing the square. \(3 x^{2}+12 x-18=0\)

Graph each inequality. $$ y \leq x^{2}+4 x $$

Solve each equation by completing the square. \(x^{2}+2 x+6=0\)

Graph each function. $$ y=-(x-5)^{2}-3 $$

Complete parts a and b for each quadratic equation. a. Find the value of the discriminant. b. Describe the number and type of roots. Do your answers for Exercises 1, 3, 5, and 7 fit these descriptions, respectively? \(x^{2}+3 x+8=5\)

Find the values of \(m\) and \(n\) that make each equation true. $$ (2 n-5)+(-m-2) i=3-7 i $$

Complete parts a-c for each quadratic function. a. Find the \(y\) -intercept, the equation of the axis of symmetry, and the \(x\) -coordinate of the vertex. b. Make a table of values that includes the vertex. c. Use this information to graph the function. $$ f(x)=x^{2}+4 $$

Graph each inequality. $$ y>x^{2}-36 $$

ELECTRICITY The current in one part of a series circuit is \(4-j\) amps. The current in another part of the circuit is \(6+4 j\) amps. Add these complex numbers to find the total current in the circuit.