Find all the 6 trig ratios for this special 30-60-90 triangle.

Pythagorean Theorem -- Used for right triangles (triangles with one right angle)

Using proportions in similar triangles -- Used for non-right triangles

Trig ratios SOH CAH TOA -- Used for right triangles

Law of sines and cosines -- Used for non-right triangles

30-60-90 and 45-45-90 triangles -- Used for right triangles

hello from mrbilldoesmath!

answer:

25x^2 + 90x + 84

discussion:

mn(x) = m(n(x)) = m( 5x + 9) =

(5x + 9)^2 + 3 =>

25x^2 + 90x + 9^2 + 3 =

25x^2 + 90x + 84                 (as 9^2 = 9*9 = 81)

which is the second choice

regards,  

mrb

p.s.   i'll be on vacation from friday, dec 22 to jan 2, 2019. have a great new year!