( B+C) : а
Вроде правильно
<span>(678+15762/426*56)/25=(678+37/56)/25=</span>
F(x) = <u>cosx</u> - <u>x² </u>
1-x 3
f(x)' = (<u>cosx</u>)' - 1/3 (x²)' = <u>(cosx)' (1-x) - cosx (1-x)'</u> - (1/3) * 2x =
( 1-x ) (1-x)²
= <u>-(1-x) sinx + cosx</u> - <u> 2x </u>
(1-x)² 3
f' (0)= <u>-(1-0) sin 0 + cos 0</u> - <u>2*0 </u>= 1/1 =1
(1-0)² 3
(19-16)*54=3*54=162(км)-S
v2-x
(162+((24-19)*54))+(24-19)x=642
(162+(5*54)+5x=642
162+270+5x=642
5x=642-432
5x=210:5
x=42(км/ч)