Tana = 3 find the square of the following formula (Sina) - 2sinacosa - (COSA) / 4 (COSA) - 3sinacosa

Tana = 3 find the square of the following formula (Sina) - 2sinacosa - (COSA) / 4 (COSA) - 3sinacosa

(Sin & # 178; a-2sinacosa-cos & # 178; a) / (4cos & # 178; a-3sinacosa)
The numerator and denominator are simultaneously divided by cos & # 178; a
The original formula = (Tan & # 178; a-2tana-1) / (4-3tana) = - 2 / 5