上浒文通大学 SHANGHAI JIAO TONG UNIVERSITY Some useful trigonometric identities: ejote-io ,sin0=-j eioe-io 2 2 1-tan2(号) 2ian(号 c0s0=- ,sin= 1+tan2(号) 1+iam(? cos(0±)=cos(0)cos(p)干sin(O)sin(p) sin(0±)=sin(θ)cos(p)±cos()sin(p)Some useful trigonometric identities: cos sin jj jj ee ee j θθ θθ θ θ − − + − 2 cos ,sin 2 2 1 () 2 () θ θ j θ θ = =− 2 2 2 1 tan () 2 tan( ) 2 2 cos ,sin 1t () 1t () θ θ θ θ θ θ − = = 2 2 1 tan () 1tan ( ) 2 2 cos( ) cos( )cos( ) sin( )sin( ) θφ θ φ θ φ + + ± = ∓ sin( ) sin( )cos( ) cos( )sin( ) θφ θ φ θ φ θ φ θ φ θφ ± = ±= ± ∓