化简已知θ是第二象限角,且sin(θ/2)|cos(θ/2)||。
θ为第二象限角,
即kπ+π/4|cos(θ/2)||cos(θ/2)||=-log|cos(θ/2)|。
∴2^|log|cos(θ/2)||
=|cos(θ/2)|^(-1)
=1/cos(θ/2)
=-sec(θ/2)
=sec(π-θ/2)。
θ为第二象限角,
即kπ+π/4|cos(θ/2)||cos(θ/2)||=-log|cos(θ/2)|。
∴2^|log|cos(θ/2)||
=|cos(θ/2)|^(-1)
=1/cos(θ/2)
=-sec(θ/2)
=sec(π-θ/2)。收起