问题 填空题 若sin(π2-θ)=13,则sin(π2+θ)=______. 答案 ∵(π2-θ)+(π2+θ)=π,sin(π2-θ)=13,∴sin(π2+θ)=sin[π-(π2+θ)]=sin(π2-θ)=13,故答案为:13.