Question

ПОМОГИТЕ СРОЧНО 47 БАЛЛОВ

Answer 1

Ответ:

Объяснение:

s₈=(a₁+a₈)*8/2=(-3+60)*4=57*4=228

S₆₇=(a₁+a₆₇)*67/2=(2+200)*67/2=101*67=6767

sin(83°+77°)=sin160°

cos(52°+78°)=cos130°

Answer 2

$\displaystyle\tt \boxed{4}\\\\ a) \ \ a_1=-3; \ \ \ a_n=60; \ \ \ n=8\\\\ S_8=\frac{a_1+a_n}{2}\cdot n= \frac{-3+60}{2}\cdot 8=57\cdot4=228\\\\\\ e) \ \ a_1=2; \ \ \ a_n=200; \ \ \ n=67\\\\ S_{67}=\frac{a_1+a_n}{2}\cdot n= \frac{2+200}{2}\cdot 67=101\cdot67=6767\\\\\\\boxed{5}\\\\\\ a) \ \sin83^o\cos77^o+\cos83^o\sin77^o=\sin(83^o+77^o)=\sin160^o\\\\ e) \cos52^o\cos78^o-\sin52^o\sin78^o=\cos(52^o+78^o)=\cos130^o$