已知(1+sinx)/cosx= -1/2 ,則cosx/(sinx-1)的值為? 請寫出解答過程!謝謝!

熱心網友

cosx^2=1-sinx^2=(1+sinx)(1-sinx)=-(1+sinx)(sinx-1)所以(1+sinx)/cosx = -cosx/(sinx-1)所以cosx/(sinx-1) = 1/2