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Basic Trigonometric Ratios

Exact values of the trigonometric ratios

• For the angles $$30^{\circ}$$, $$45^{\circ}$$ and $$60^{\circ}$$ we can find the exact values for the trigonometric ratios.
• These ratios are given in the Table below:

 $$\theta$$ $$30^{\circ}$$ $$45^{\circ}$$ $$60^{\circ}$$ $$\sin\theta$$ $$\frac{1}{2}$$ $$\frac{1}{\sqrt{2}}$$ $$\frac{\sqrt{3}}{2}$$ $$\cos\theta$$ $$\frac{\sqrt{3}}{2}$$ $$\frac{1}{\sqrt{2}}$$ $$\frac{1}{2}$$ $$\tan\theta$$ $$\frac{1}{\sqrt{3}}$$ $$1$$ $$\sqrt{3}$$

Using these triangles assists in remembering these ratios.