EQUIVALENT TRIGONOMETRY EXPRESSION

EQUIVALENT TRIGONOMETRY EXPRESSION

Don’t panic looking at the title. It is a lot simpler then it looks. So let’s begin…J

FIRST OF ALL, let’s look a triangle… J of course after this example u will have to use a unit circle to further your understanding…but here goes

Example :

sinx = a/b 

Given ∠C = π/2 – x

sin ∠C = c/b

cos ∠C = a/b 

tan ∠C = c/a

Therefore,

sinx = cos ∠C , sinx = cos (π/2 – x)

Using the same techniques above… it can be deduced that it is possible to derive a few other similar trigo expressions:

x+(π/2)	π-x
sin x = -cos (X+(π/2))	sin x = sin (π-x)
cos x = sin (X+(π/2))	Cos x = -cos (π-x)
tan x = =cot (X+(π/2))	Tan x = -tan (π-x)
x+π	(π/2)-x
sin x = -cos (x+π)	sin x = cos ((π/2)-x)
cos x = -sin (x+π)	cos x = sin ((π/2)-x)
tan x = cot (x+π)	tan x = cot ((π/2)-x)

Therefore, I know the stuff above is scary looking and all. But honestly the truth is HARD and thus YOU HAVE TO REMEMBER it!! Hehehe… on that note, I hope listing it all out in different colors helps. It helps a ‘lil in my case… but honestly, cramming all that stuff ain’t gonna be easy… hence, I took the liberty to find a parody to do with trigo ( I am sure u all knot the GLEE song “Don’t Stop Believing” J)that just might cheer u up… ALL THE BEST GUYS!!!