cos(-x) = cos(x)

sec(-x) = 1/cos(-x) = 1/cos(x)

sec(-x)cos(-x) = (1/cos(x))cos(x) = 1

sec (-x) cos (-x)

= 1

( 1 )

sec(-x) cos(-x) =

cos(-x)/cos(-x) =

1

Answer is 40

1

1 since sec = 1/cos

.