Trigonometry Sheet 3
ASTC Quadrant Formulas (All 78 Results)
ASTC Rule: Q1 (All +ve) | Q2 (Sin/Cosec +ve) | Q3 (Tan/Cot +ve) | Q4 (Cos/Sec +ve)
1. Vertical Axis: $$90^\circ$$&$$270^\circ$$ (Ratios Change)
$$\sin \leftrightarrow \cos$$, $$\tan \leftrightarrow \cot$$, $$\sec \leftrightarrow \csc$$
| Angle (θ) | $$\sin$$ | $$\cos$$ | $$\tan$$ | $$\csc$$ | $$\sec$$ | $$\cot$$ |
|---|---|---|---|---|---|---|
| $$90^\circ – \theta$$ (Q1) | $$\cos\theta$$ | $$\sin\theta$$ | $$\cot\theta$$ | $$\sec\theta$$ | $$\csc\theta$$ | $$\tan\theta$$ |
| $$90^\circ + \theta$$ (Q2) | $$\cos\theta$$ | $$-\sin\theta$$ | $$-\cot\theta$$ | $$\sec\theta$$ | $$-\csc\theta$$ | $$-\tan\theta$$ |
| $$270^\circ – \theta$$ (Q3) | $$-\cos\theta$$ | $$-\sin\theta$$ | $$\cot\theta$$ | $$-\sec\theta$$ | $$-\csc\theta$$ | $$\tan\theta$$ |
| $$270^\circ + \theta$$ (Q4) | $$-\cos\theta$$ | $$\sin\theta$$ | $$-\cot\theta$$ | $$-\sec\theta$$ | $$\csc\theta$$ | $$-\tan\theta$$ |
2. Horizontal Axis & Periodicity (Ratios Remain Same)
| Angle (θ) | $$\sin$$ | $$\cos$$ | $$\tan$$ | $$\csc$$ | $$\sec$$ | $$\cot$$ |
|---|---|---|---|---|---|---|
| $$180^\circ – \theta$$ (Q2) | $$\sin\theta$$ | $$-\cos\theta$$ | $$-\tan\theta$$ | $$\csc\theta$$ | $$-\sec\theta$$ | $$-\cot\theta$$ |
| $$180^\circ + \theta$$ (Q3) | $$-\sin\theta$$ | $$-\cos\theta$$ | $$\tan\theta$$ | $$-\csc\theta$$ | $$-\sec\theta$$ | $$\cot\theta$$ |
| $$360^\circ – \theta$$ (Q4) | $$-\sin\theta$$ | $$\cos\theta$$ | $$-\tan\theta$$ | $$-\csc\theta$$ | $$\sec\theta$$ | $$-\cot\theta$$ |
| $$360^\circ + \theta$$ (Q1) | $$\sin\theta$$ | $$\cos\theta$$ | $$\tan\theta$$ | $$\csc\theta$$ | $$\sec\theta$$ | $$\cot\theta$$ |
| $$2n\pi + \theta$$ (Q1) | $$\sin\theta$$ | $$\cos\theta$$ | $$\tan\theta$$ | $$\csc\theta$$ | $$\sec\theta$$ | $$\cot\theta$$ |
| $$2n\pi – \theta$$ (Q4) | $$-\sin\theta$$ | $$\cos\theta$$ | $$-\tan\theta$$ | $$-\csc\theta$$ | $$\sec\theta$$ | $$-\cot\theta$$ |
| $$-2n\pi + \theta$$ (Q1) | $$\sin\theta$$ | $$\cos\theta$$ | $$\tan\theta$$ | $$\csc\theta$$ | $$\sec\theta$$ | $$\cot\theta$$ |
| $$-2n\pi – \theta$$ (Q4) | $$-\sin\theta$$ | $$\cos\theta$$ | $$-\tan\theta$$ | $$-\csc\theta$$ | $$\sec\theta$$ | $$-\cot\theta$$ |
| $$-\theta$$ (Q4) | $$-\sin\theta$$ | $$\cos\theta$$ | $$-\tan\theta$$ | $$-\csc\theta$$ | $$\sec\theta$$ | $$-\cot\theta$$ |