Question

Lim
x->phi/4

cos 2x / cos x - sin x

Answer 1

=cos^2 x - sin^2 x/cos x - sin x
=(cos x - sin x) (cos x + sin x)/cos x - sin x
=coret maka: cos x + sin x
=cos 45 + sin 45
=1/2 √2 + 1/2√2
=√2