Question

please solve this sum​

Answer 1

$\sec( \alpha ) - \tan( \alpha ) \binom{ \sec( \alpha + \tan( \alpha ) ) }{?}$

=1/4

1/cos-sin/cos/1/cos+sin/cos=1/4

1-sin/1+sin=1/4

4-4sin=1+sin

4-4sin-1-sin=0

3-3sin=0

sin=1

pi/2 is the answer of this question