Xn = x1 + (n-1)*d
n = ?
(xn-x1 +d) = n*d
(xn-x1+d)/d = n
n = (-2.6 - 8.2 - 0.3) / (-0.3) = 37
Sin(180-2a)=sin(2a)=2sin(a)*cos(a)=2*корень(1-0,2^2)*0,2=2*корень(1-(1/5)^2)*0,2
=2*1/5*корень(24)*0,2=4/25*корень(6)~<span>
0,391918
</span>
–
=
(10–a)
a) 121(10–11) = 121×(–1) = –121
b) 81(10–9) = 81×1 = 81