Brad M. answered • 05/14/13

100+ Sessions in Precal-Trig-Alg 2: B'burg-Salem HS, RU MATH 138

Hi Tracy -- I attended Horseheads High school and will be visiting the area in coming weeks.

Sometimes it's helpful simply to plug in directly the triangle sides in each of these ratios:

secx=hyp/adj, tanx=opp/a, sinx=opp/h

h/a - opp/a(opp/h)= a/h ==> a*a/h= h*h/h - opp*opp/h :

factor out 1/h ==> a*a= h*h - opp*opp which is the <a^2 + b^2 = c^2> identity.

Any trig identity with the sides actually plugged in should land here ... Regards & send me an Email :)

John C.

09/23/13