Question

按照規(guī)律(t是參數(shù))運(yùn)動(dòng)后,質(zhì)點(diǎn)從時(shí)間t₁到t₂經(jīng)過(guò)的距離是_________.

Answer 1

解析:時(shí)間t₁對(duì)應(yīng)的點(diǎn)A的坐標(biāo)是(a+t₁cosθ,b+t₁sinθ),時(shí)間t₂對(duì)應(yīng)的點(diǎn)B的坐標(biāo)是(a+t₂cosθ,b+t₂sinθ),利用兩點(diǎn)距離公式可以求得質(zhì)點(diǎn)從時(shí)間t₁到t₂經(jīng)過(guò)的距離

|AB|=

=

=|t₁-t₂|.

答案:|t₁-t₂|.