


Mrs. Brenda Overholt
Math Department
Franklin County High School
700 Tanyard Road
Rocky Mount, Virginia 24151


Choosing the Trig
Function



All right triangle trigonometry problems use this formula:
Rule: The trig
function is based on the two sides you decide to use. Replace TrigFunction
in the formula with either sin,
cos,
or tan.
Choice: There
are three of them!




Decide where you'll be standing

Look at the sides you have in the problem.

Decide which two you'll be using (Hint)

Then using Oscar or Sohcahtoa, decide which trig function would be best.







Decide where you'll be standing

Look at the sides you have in the problem.

Decide which two you'll be using (Hint)

Then using Oscar or Sohcahtoa, decide which trig function would be best.







Decide where you'll be st__________.

Look at the si___ you have in the problem.

Decide which two you'll be using (Hint)

Then using Oscar or Sohcahtoa, decide which trig f_______ would be best.






This problem is a little different. You might choose to stand
at M or N. BUT either way, the trig function will be the same!
Which one? 


sin x or sin y 
cos x or cos y 
tan x or tan y 


Next: Setting up a Trig Function equation
[ tutorial  examples
 standing choice  function choice  equation
]




brenda.overholt@frco.k12.va.us
August, 2004
