Question

If cot=7/8 then find (1+sin )×(1-sin)+(1+cos)×(1-cos)

Answer 1

(1+8/√113)(1-8/√113)+(1+7/√113)(1-7/√113)

[(√113+8)(√113-8)]/113+[(√113+7)(√113-7)]/113

(113-64)/113+(113-49)/113

49/113+64/113
113/113
=1