How do you simplify sec^2x (1-sin^2x)?

1
From trig identities ##sin^2x+cos^2x=1##
##therefore 1-sin^2x=cos^2x##
##therefore sec^2x(1-sin^2x)=sec^2x*cos^2x##
##=1/(cos^2x)*cos^2x##
##=1##