$$1 \le A \le 2$$

$${3 \over 4} \le A \le 1$$

$${13\over 16} \le A \le 1$$

$${3 \over 4} \le A \le {{13} \over {16}}$$

no real solution

one real solution

more than one solution

none of these

$$ - {4 \over 5}\,but\,not\,{4 \over 5}$$

$$ - {4 \over 5}\,or\,{4 \over 5}$$

$${4 \over 5}\,\,but\,not\, - {4 \over 5}$$

None of these.

$$tan{\alpha \over 2} + \tan {\beta \over 2} + \tan {\gamma \over 2} = \tan {\alpha \over 2}\tan {\beta \over 2}\tan {\gamma \over 2}$$

$$\tan {\alpha \over 2}\tan {\beta \over 2} + \tan {\beta \over 2}\tan {\gamma \over 2} + \tan {\gamma \over 2}\tan {\alpha \over 2} = 1$$

$$tan{\alpha \over 2} + \tan {\beta \over 2} + \tan {\gamma \over 2} = - \tan {\alpha \over 2}\tan {\beta \over 2}\tan {\gamma \over 2}$$

None of these.