Question

sec(45°+a)sec(45°-a)=2sec2a

Answer 1

Step-by-step explanation:

sec(45°+a)sec(45°-a)

=1/cos(45°+a).1/cos(45°-a)

=1/cos^2(45°)- sin^2a

=1/1/2-sin^a

=2/1- 2sin^a

=2/cos2a

=2sec2a