我全力准备三角学

i am fully preparing for trigonometry.

或者是

i am fully preparing to study trigonometry

be prepared to do sth的意思是已经做好准备干某事.

I'm preparing for triaonometry with all my heart.

I'm doing my level best to prepare for the trigonometry.

do one's level best 是全力以赴的意思.