If cos 13 +sin 13/cos 13 - sin 13 = tan a then find a Share with your friends Share 2 Ashutosh Verma answered this Answer : Cos 13° + Sin 13°Cos 13° - Sin 13° = tan a So we simplify , As : ⇒Cos 13° 1 + Sin 13°Cos 13°Cos 13° 1 - Sin 13°Cos 13° = tan a⇒ 1 + tan 13° 1 - tan 13° = tan a ( As we know Sin θCos θ = tan θ ) ⇒ 1 + tan 13° 1 - 1 × tan 13° = tan a ⇒ tan 45° + tan 13° 1 - tan 45° × tan 13° = tan a ( As we know tan 45° = 1 )⇒tan ( 45° + 13° ) = tan a ( As we know tan A + tan B 1 - tan A × tan B = tan ( A + B ) ) ⇒tan ( 58° ) = tan aSO,⇒a = 58° ( Ans ) 5 View Full Answer