Posted by May on Monday, January 11, 2010 at 7:15pm.
Hi, could someone explain to me how to use a counterexample in trig to prove whether something is either an identity or equation?
For ex. how would you do that with this question?
sec^2xtan^2x= cos x

Math gr.12 Trig.  Marth, Monday, January 11, 2010 at 8:13pm
A counterexample is simply any instance that disproves the statement.
For example, try using x = pi/4. Note that this is NOT the only correct answer.

Math gr.12 Trig.  May, Monday, January 11, 2010 at 8:19pm
Would I substitute the same number to both sides?
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