SOLUTION: Tim claims he created a new trigonometric identity. Tasha tested it by plugging 30o in for theta and found that both sides of the equation worked out to 2. She said that this pro

Algebra ->  Rational-functions -> SOLUTION: Tim claims he created a new trigonometric identity. Tasha tested it by plugging 30o in for theta and found that both sides of the equation worked out to 2. She said that this pro      Log On


   

Question 1201895: Tim claims he created a new trigonometric identity. Tasha tested it by plugging 30o in for theta and found that both sides of the equation worked out to 2. She said that this proves his equation is an identity. Is Tasha’s reasoning correct? Explain.
Answer by ikleyn(52906) About Me  (Show Source):
You can put this solution on YOUR website!
.

The notion "identity" assumes that both sides are equal at all/(at any) values
of the argument in the entire given/claimed interval/domain,

while Tasha checked it for one single value of the argument,

which is not enough to consider Tasha's arguments as a proof.