What does "d2" mean in trigonometry?

Will give brainliest! 2017 amc 12a problem 24 quadrilateral [tex]abcd[/tex] is inscribed in circle [tex]o[/tex] and has side lengths [tex]ab=3, bc=2, cd=6[/tex], and [tex]da=8[/tex]. let [tex]x[/tex] and [tex]y[/tex] be points on [tex]\overline{bd}[/tex] such that [tex]\frac{dx}{bd} = \frac{1}{4}[/tex] and [tex]\frac{by}{bd} = \frac{11}{36}[/tex]. let [tex]e[/tex] be the intersection of line [tex]ax[/tex] and the line through [tex]y[/tex] parallel to [tex]\overline{ad}[/tex]. let [tex]f[/tex] be the intersection of line [tex]cx[/tex] and the line through [tex]e[/tex] parallel to [tex]\overline{ac}[/tex]. let [tex]g[/tex] be the point on circle [tex]o[/tex] other than [tex]c[/tex] that lies on line [tex]cx[/tex]. what is [tex]xf\cdot xg[/tex]? show all work!

Write the expression in complete factored form. 5n_(c - 3) - n(c - 3) =

Write as a product of two polynomials. 2(3–b)+5(b–3)^2