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V1*630 = v2*504
v2 = v1*630/504
<span>v2 = 1.25*v1 </span>
A) f'(x) = 3/√(Cos2x) * 1/2√Cos2x) *(-Sin2x) * 2 = --3Sin2x/Cos2x = -3tg2x
б) f'(x) = ( 1/7 * (x-9)^7* Сos2πx)' - (1/πCos³πx/4)'=
= (x-9)^6 * Cos2πx + 1/7 * (x-9)^7 * (-Sin2πx) * (-2) +2Cos^-1 πx/4* (-Sinπx/4 )* π/4.
f'(9) = Cos18π - π/2 Sin9π/4 /Cos9π/4= 1 - π/2
1) -3°С
-4.5°С
-5°С
+2,5°С <em>(возможно +2,3)</em>
2) 7 ч
10 ч и 22:30 ч
13 ч и 19:30 ч
17-5(х-2,2)=4-7х
17-5х+11=4-7х
-5х+7х=4-17-11
2х=-14
х=-7
Ответ: х=-7