Oxford Mathematics Admissions Test - Some trigonometric inequalities

[@RajSandhu-gm8iz]

Hi, just come across your channel, great videos. This question is a variation of the classic proof of limit x to zero of sinx/x=1 found in most A Level maths textbooks. Area triangle OAC

[@mathoutloud]

Certainly! The exam this comes from has some follow up questions, one of which involves that limit.

[@mscha]

Note that ∠ACB is 𝘯𝘰𝘵 a right angle! It it were, then so would ∠ACO, and because of symmetry (OA = OC = 1), so would ∠CAO. That would mean ∠AOC = 𝑥 = 0.

[@mathoutloud]

Oh, goodness, you're right. I totally messed that up. I'll add a comment to the description, thanks for pointing this out. Luckily I don't end up using that in my solution, but still a pretty silly mistake to make.