Today’s question looks sooo simple. Just punch those keys on your state-of-the-art Casio scientific calculator and you will get it right … except that this is a Paper 1 question and your favourite Casio calculator should not be there!
So how now? Go ask your Grandma (Ah SOH) with the big foot (TOA CAH) for help lah!
In the diagram, a ladder BC is leaning against the wall AD. Given that, sin x = 5/13. Find the cosine of angle DCB.

Miss Loi is a full-time private tutor in Singapore specializing in O-Level Maths tuition. Her life’s calling is to eradicate the terrifying LMBFH Syndrome off the face of this planet. For over years she has been a savior to countless students … 




















