3. The exponential function (a+s)t Le-au( d=j -la+s)t (a+s)0 s+a 1 s-+Oc 4. The ramp function tu(t {u(t)} e at 2 tl(1)<>-23. The exponential function    + =  − + = − + s s e s t 1 ( ) 0 ( )   + −  s e t 1 4. The ramp function t u(t)   2 0 1 ( ) s L t u t t e dt st   − = = 2 1 ( ) s tu t  Le u(t) −t   − − = 0 e e dt st  t   − + = 0 ( ) e dt  s t