Sinθ0,cosθ& gt; 0
Journal? (sinθ)、log? (cosθ) makes sense
2kπ& lt; θ& lt; 2kπ+π/2,(k∈Z)
(sinθ+cosθ)? =(√2)?
Sin? θ+cos? θ+2sinθcosθ=2
1+2sinθcosθ=2
sin2θ= 1
4kπ& lt; 2θ& lt; 4kπ+π,(k∈Z)
2θ=4kπ+π/2,(k∈Z)
θ=2kπ+π/4,(k∈Z)
sinθ=√2/2=2^(-? ),cosθ=√2/2=? ^(? )
Journal? (sinθ)log? (cosθ)
= log? [? ^(? )] log? [? ^(? )]
=? ?
=?
A proposition is a true proposition.