512 



CAMBRIA STEEL. 



TRIGONOMETRIC FORMULAE. 

 TRIGONOMETRIC FUNCTIONS. 



JH K Q Let A = angle BAG = arc BF. 



Let radius AF = AB = AH = 1. 



Then 



sin A =BC versin A =CF = BE 

 cos A =AC covers A =BK = HL 

 tan A =DF exsec A =BD 

 cot A =HG coexsec A = BG 

 sec A =AD chord A =BF 

 cosec A = AG chord 2 A = B I = 2BC 



RIGHT-ANGLED TRIANGLES. 



In the right-angled triangle ABC, 

 Let side AB=c, side AC = b, and side 

 BC = a; let angle ABC = B. 



a = c sin A = b tan A 



b = c cos A = a cot A 



a b 



sin A cos A 



a = c cos B = b cot B 



b = c sin B=a tan B 

 a b 



cosec A = -'- = sec 

 a 



vers A = = covers B 



cos B sin B 



. = V(c+b) (c-b) 



c b 

 exsec A = ; = coexsec B 



V(c-f-a) (c-a) 



A c a . _ 



covers A = = versin B 



A c a _ 



coexsec A = = exsec B 



a 



ab a 

 Area= = \ c 2 -a 2 = 



C = 90 = . 



a 2 cot A b 2 tan A c 2 sin 2A 



2 



