Trigonometry Essentials
Knowing the exact trigonometric values for common angles will save you tons of time in exams! For angles 0ยฐ, 30ยฐ, 45ยฐ, 60ยฐ and 90ยฐ, there are specific values for sine, cosine and tangent that you should memorise rather than calculate each time.
The fundamental trigonometric ratios relate the sides of a right-angled triangle: sine = opposite/hypotenuse, cosine = adjacent/hypotenuse, and tangent = opposite/adjacent. These are the building blocks for solving any triangle problem you'll encounter.
A clever way to remember these values is using the "finger trick" - counting from your thumb (0ยฐ) to your pinky (90ยฐ). For sin, the values start at 0 and increase (0, 1/2, โ2/2, โ3/2, 1), while for cos, they decrease from 1 to 0 (1, โ3/2, โ2/2, 1/2, 0).
Remember This: Trig values appear everywhere in maths and physics! When you see sin60ยฐ, you should immediately know it equals โ3/2 without needing a calculator.
When working with angles beyond 90ยฐ, you'll need to understand how these values repeat in patterns. Sine and cosine have a period of 360ยฐ, while tangent repeats every 180ยฐ. This knowledge is crucial for sketching graphs and solving equations involving trigonometric functions.