Question

Prove that
cos 15° - sin 15° 1
cos15° + sin 15° =1/√3​

Answer 1

LHS = (cos15- sin15)/(cos15+sin15)

= [(cos15-sin15)(cos 15-sin15)]/

[(cos15+sin15)(cos 15-sin15)]

= (Cos15-sin15 )2/( cos²15 - sin² 15 )

= [cos²15+sin² 15-2sin15cos15]/cos(2x15)

= [1-sin (2x15 )]/ cos30

= (1-sin30) / cos30

= (1-1/2)/(√3/2)

= (1/2)/(√3/2)

= 1/√3

= RHS

Please Mark Me As BRAINLEST ❤️