sin 2 x + cos 2 x = 1 {\displaystyle \sin ^{2}x+\cos ^{2}x=1} 1 + cot 2 x = csc 2 x {\displaystyle 1+\cot ^{2}x=\csc ^{2}x} 1 + tan 2 x = sec 2 x {\displaystyle 1+\tan ^{2}x=\sec ^{2}x}
t a n x = ( s i n x ) / ( c o s x ) {\displaystyle tanx=(sinx)/(cosx)} c o t x = ( c o s x ) / ( s i n x ) {\displaystyle cotx=(cosx)/(sinx)}