Question

证明,[1+sinα）/（1+cosα）]*[（1+secα）/（1+cscα）]=tanα

Answer 1

左=[(1+sinα)/(1+cosα)] *[(1+1/cosα)/(1+1/sinα)]

=[(1+sinα)/(1+cosα)]*[(cosα+1)/cosα]/[(sinα+1)/sinα]

=[(1+sinα)/(1+cosα)]*[(cosα+1)sinα]/[(sinα+1)cosα]

=sinα/cosα

=tanα