Question

根号(1+tan^2 6度)*sin84度

Answer 1

1+(tan6)^2

=1+(sin6)^2/(cos6)^2

=[(sin6)^2+(cos6)^2]/(cos6)^2

=1/(cos6)^2

所以原式=(1/cos6)*sin84

=(1/cos6)*sin(90-6)

=(1/cos6)*cos6

=1