Question

$\huge{Evaluate the following.\ 2tan^2 45° + cos^2 30° - sin^2 60°}$

Answer 1

with trignometric angle table

Answer 2

2 tan²45° + cos²30° - sin²60°

[ tan 45 = 1 ]

==> 2 × 1 + cos²30° - cos²(90-30)

==> 2 + cos²30° - cos²30° [ cos A = cos ( 90 - B) ]

==> 2

The answer is 2