as the title says guys i am in a big trouble and i need your help i have my maths exam tomorrow and i have these two questions that i can't answer so if anyone can help me i will reeeeeeeeeally appreciate it and do anything i can to help when they need some so the questions are Q1/ prove that tan(x/2)=(1-cosx)/sinx Q2/find the value of : sin22.5 cos22.5 without using a calculator ps :thanks for bothering to open this