Homework Help: Math- gr.12 Trig.

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^2x-tan^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?

Answer this Question

Related Questions

gr 12. advanced functions - Trig identity Prove: cos2x tan(pie/4 - x...
trig - Write the expression and evaluate. There is only one answer whIch should ...
trig - The terminal side of an angle includes the point (5,-12). Give the sine, ...
math - could someone please refresh my memory of the basic trig functions? ex) ...
Math - Trig - Hi I have a Trig question that i dont understand, can someone ...
trig - Prove the following trig identity: 1 + sinx = sinx(1+cscx)
trig - Write the expression and evaluate. There should only be one answer which ...
Trigonometry - Use the trig Identities to find the other 5 trig functions. ...
Precalculus - How would you solve this trig function: cos2x=sin^2-2 how do you ...
trig - prove the trig identity cos(4x) = 2-sec^2(2x)/sec^2(2x)

For Further Reading

First Name:
School Subject:
Answer: