例题3-3:平移一翻转一長缩 ●x()如图所示, 求x(-2t-2) 右移b=2→xt-2) 012 4 翻转t→(-1x(-t-2) 压缩a=2x(2t-2) X(-2t-2)=x[-2(t+2/2) =X[2(t+1)
x(t) t -4 -2 0 1 2 2 例题3-3: 平移-翻转-展缩 ⚫ x(t)如图所示, 求x(-2t-2). ⚫ 右移 b=2→x(t-2) ⚫ 翻转 t → (-t):x(-t-2) ⚫ 压缩 a=2→x(-2t-2) ⚫ x(-2t-2)=x[-2(t+2/2)] =x[-2(t+1)] 4