Question

.)
Show that tan 48° tan 23° tan 42° tan 67° = 1​

Answer 1

$\huge{\pink{\bigstar{\mathfrak{solution}}}}$

$\star \sf \: to \: prove :$

$tan48° \tan23° \tan42° \tan67 \degree = 1$

$\star \sf \: proof :$

$\tan(90 - 42) \tan(90 - 61) \tan(42) \tan(67)$

$\cot(42) \cot(67) \tan(42) \tan(67)$

$\cot(42) \tan(42) \cot(67) \tan(67)$

$1 \times 1$

$= 1$

Hence proved //