质点运动方程是S=t^2(1+sint),则当x=π/2时,瞬时速度为

Question

质点运动方程是S=t^2(1+sint),则当x=π/2时,瞬时速度为____________

Answer 1

解由S=t^2(1+sint),求导函数S′=[t^2(1+sint)]′=2t（1+sint）+t²(1+sint)′=2t（1+sint）+t²(cost)即当t=π/2时,瞬时速度为S在t=π/2时的导数为S′（π/2）=2*π/2*（1+sinπ/2）+（π/2）²(cosπ/2...