Q=b2/b1=-24/-12=2
b1•(q^7–1) -12•127
S7 = --------------- = ----------- = –1524
q–1 1
Надеюсь поймешь мой почерк
Sin22°30'=± √1/2(1-Cos45°)= ±√1/2(1-√2/2)= ±√(1/2 - √2/4)=±√((2 - √2)/4)=
=±√(2-√2)/2
Cos22°30'= ±√(1-Sin²22°30')= ±√((1-2 +√2)/4)= ±√(√2 -1) /2
tg22°30' = Sin22°30'/Cos22°30' = ±√(2-√2)/2/±√(√2 -1) /2= ±√(2-√2)/√(√2 -1)