Question

(cos / 1-sin) -(cos/1+sin) = 2 tan

Answer 1

cosФ/1-sinФ - cosФ/1+sinФ =2tanФ

by taking L.C.M

= cosФ(1+sinФ)-cosФ(1-sinФ) /1²-sin²Ф

= cosФ+cosФsin-cosФ+cosФsinФ/1-sin²Ф

= +cosФ cancels - cosФ,

now we have ,

= 2cosФsinФ/cos²Ф           {1-sin²Ф= cos²Ф}

= 2sinФ/cosФ

= 2tanФ

hence proved !

hope you understand!! if not plz ask ...