Signal processing : Energy signals

Discussion in 'Homework Help' started by nyasha, Sep 24, 2011.

  1. nyasha

    Thread Starter Active Member

    Mar 23, 2009
    Question : For an energy signal x(t) with energy Ex, show that the energy of x(-t) is also Ex.

    My problem : In the attached solutions l do not understand why they first substitute t1=-t and then a few lines later they substitute t1=t. Please explain this to me.