Iknow a little bit but i still need this morning in graphing

Enter the number of complex zeros for the polynomial function f(x) = x 4+ 5x² +6

Since opening night, attendance at play a has increased steadily, while attendance at play b first rose and then fell. equations modeling the daily attendance y at each play are shown below, where x is the number of days since opening night. on what day(s) was the attendance the same at both plays? what was the attendance? play a: y = 8x + 191 play b: y = -x^2 + 26x + 126

Evaluate cos2θ for cosθ = square root of 3/2