Which are the solutions of the quadratic equation?
x2=7x+4
-7-165 -7 + 165
-7.0
7- 165 7+ / 65
7,0

For the experiment done in lab, recall that applying σfx = max to the ball gives the equation fstring = m4π2f 2l. combine this result with the result of applying σfy = may and derive an equation for sin θ in terms of f and l. θ is the angle between the string and the horizontal.