PART - 1 CH - 3 Trigonometric Functions MATHS - PART - 1 CH - 3 Trigonometric Functions

• ✓
  $\tan \frac{\alpha}{2}+\tan \frac{\beta}{2}+\tan \frac{r}{2}=\tan \frac{\alpha}{2} \tan \frac{\beta}{2} \tan \frac{r}{2}$
• B
  $\tan \frac{\alpha}{2}+\tan \frac{\beta}{2}+\tan \frac{r}{2}=-\tan \frac{\alpha}{2} \tan \frac{\beta}{2} \tan \frac{r}{2}$
• C
  $\tan \frac{\alpha}{2} \cdot \tan \frac{\beta}{2}+\tan \frac{\beta}{2} \tan \frac{r}{2}+\tan \frac{r}{2} \cdot \tan \frac{\alpha}{2}=1$
• D
  $\tan \alpha \cdot \tan \beta+\tan \beta \cdot \tan r+\tan r \cdot \tan \alpha=1$

Answer: A.

• A
  $-\frac{133}{205}$
• ✓
  $-\frac{84}{205}$
• C
  $\frac{84}{205}$
• D
  $\frac{133}{205}$

Answer: B.

• ✓
  $60^{\circ}, 120^{\circ}, 240^{\circ}, 300^{\circ}$
• B
  $60^{\circ}, 120^{\circ}, 240^{\circ}, 315^{\circ}$
• C
  $60^{\circ}, 150^{\circ}, 240^{\circ}, 300^{\circ}$
• D
  $60^{\circ}, 120^{\circ}, 210^{\circ}, 315^{\circ}$

Answer: A.

• A
  $\frac{\sqrt{3}}{2}$
• B
  $-\frac{1}{2}$
• ✓
  $\frac{1}{2}$
• D
  $\frac{1}{\sqrt{2}}$

Answer: C.

• A
  $\cos ( A + B )-\cos ( A - B )$
• ✓
  $\cos ( A + B )+\cos ( A - B )$
• C
  $\cos (A-B)-\cos (A+B)$
• D
  None of the above

Answer: B.