Verifying A Trig Identity Step By Step


An excellent teacher from my past said that verifying a Trig Identity was frequently a little bit of trig and a LOT of Algebra.

To verify or prove the trigonometric identity that follows, one can do the following steps:

1. Rewrite the left side, which is the sum of two reciprocal trig functions ( cscx and cotx ) ,in terms of sinx and cosx.

2. The preceding step will give you a common denominator.

3. Multiply the resulting fraction top and bottom by sinx.

4. The preceding step is confusing but justified by the fact that sin^2x = 1-cos^2x which is a pythagorean Identity.

5. Now we use the difference of two squares factoring formula in the next to last step to get a cancellation of a common factor in numerator and denominator which ends up verifying the identity.

Verify a Trig Identity Using a Pythagorean Identity

2 comments on “Verifying A Trig Identity Step By StepAdd yours →

    1. Miami Southridge Senior High School Miami, Florida. Pricipal Humberto J. Miret has to be exceedingly proud of rapping algebra teacher Brandon for his exceptional performance on Wheel of Fortune!

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