Question

show that tan 48 × tan 23 × tan 42 × tan 67 = 1​

Answer 1

$\textbf{SOLUTION}$

tan 48°×tan 23°×tan 42°×tan 67°=1

—› tan48°×tan42°×tan67°×tan23°=1

—› tan48°×tan(90°–48°) ×tan67°×tan(90°–67°)=1

—› tan48°×cot48° × tan67°×cot67°=1

—› tan48°×1/tan48° × tan67°×1/tan67°=1

—› 1×1=1

—›1=1

LHS = RHS

Answer 2

hence proved

here is your answer