One of my Sec 4 girl send me these proving trigo identities questions few days ago.
I am so sorry I have been very busy with tutors referrals and CNY preparation that I can only reply today. 🙂
Decided to post the solutions up on the blog since I have a little time this afternoon as my tuition is cancelled. 🙂
Pardon me for the low quality images. I just did the questions on my whiteboard, take pictures with my mobile phone and uploaded here. Keke.
Happy Lunar New Year to all! 🙂