Question

sin(50+thita) -cos(40- thita)+ tan1×tan10×tan20×tan70×tan80×tan89​

Answer 1

Explanation:

sin(50+O)-cos(4o-O)+tan1×tan10×tan 20×tan70×tan80×tan89

= Sin[90-(40-O)]-cos(40-O) + tan(90-80)×tan(90-89)×tan(90-70)×tan 70×tan80×tan89

= cos(4o-O)-cos(40-O)+cot89×tan89×cot80×tan80×cot70×tan 70

= 0+1/tan89×tan89×1/tan80×tan80×1/tan 70×tan 70

= 1