This deep dive covers Memory Tricks within Exact Trig Values for GCSE Mathematics. Revise Exact Trig Values in Geometry & Measures for GCSE Mathematics with 14 exam-style questions and 4 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 3 of 7 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Memory Tricks
1
Sin goes: 0, 1/2, √2/2, √3/2, 1 (pattern: √0/2, √1/2, √2/2, √3/2, √4/2)
2
Cos is sin BACKWARDS: 1, √3/2, √2/2, 1/2, 0
3
Tan = sin ÷ cos (use this to derive if you forget)
Practice questions for Exact Trig Values
What is the exact value of sin 30°?
James says that sin 30° and cos 60° are equal. Is James correct? Explain your answer using exact values.
Quick recall flashcards
Sin Pattern
sin 0°=0, sin 30°=1/2, sin 45°=√2/2, sin 60°=√3/2, sin 90°=1. Pattern: √n/2 for n=0,1,2,3,4
Cos Pattern
Cos is sin BACKWARDS. cos θ = sin(90°-θ). So cos 30° = sin 60°, etc.