Geometry
Pythagorean Identities
Given \( \sin^2(\theta) + \cos^2(\theta) = 1 \), which of the following is true?
True or False: \( \sin^2(\theta) - \cos^2(\theta) + 1 = 2\sin^2(\theta) \).
(Hint: Use the identity \( \sin^2(\theta) + \cos^2(\theta) = 1 \).)
Which is these is equivalent to \( \cos^2(\theta)\sec^2(\theta) - \cos^2(\theta),\) over values of \(\theta\) for which the given expression is defined?
Which of these is equivalent to \( x \)?
If \( \sin^2(\theta) = \frac{9}{25} \), what is \( \cos^2(\theta) ?\)