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Brad M. | Summer Online Finance Specialist: WACC NPV DCF TVM YTMSummer Online Finance Specialist: WACC ...
4.9 4.9 (233 lesson ratings) (233)

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 :)


Robert J. | Certified High School AP Calculus and Physics TeacherCertified High School AP Calculus and Ph...
4.6 4.6 (13 lesson ratings) (13)


= cosx(sec^2 x - tan^2 x), factor out cosx

= cosx, since sec^2 x - tan^2 x = 1

= 1/secx