Question

помогите, пожалуйста

Answer 1

$x(t) = {t}^{3} + 1 \\ v(t) = x'(t) = 3 {t}^{2} \\ x(t) = 9 \: м \implies {t}^{3} + 1 = 9 \\ {t}^{3} = 8 \implies t = \sqrt[3]{8} = 2 \: с\\ v(2) = 3 \times {2}^{2} = 12 \: м/с$