Question

数学帝进来帮小弟一个忙

已知(1+sinx)/cosx=-1/2 则cosx/(sinx-1)的值多少啊 先谢过大家了
还有一题 cos阿鲁法=tan阿鲁法 则sin阿鲁法的值是多少啊

Answer 1

第二题
∵tan α=(sin α)/(cos α)
又∵tan α=cos α
∴tan α=(sin α)/(cos α)=cos α
sin α=(cos α)*(cos α)
∵(sin α)*(sin α)+(cos α)*(cos α)=1
∴(sin α)*(sin α)+(cos α)*(cos α)=(sin α)*(sin α)+sin α=1
解得：sin α=（-1±根号5）/2
∵|sin α|≤1,且sin α=(cos α)*(cos α)
∴sin α=（-1+根号5）/2