CPM Homework Help : PC Problem 4-72

Use the Fundamental Pythagorean Identity to simplify each trig expression.

Hint:

Pythagorean Identities are squared sine of x + squared cosine of x = 1, squared tan of x + 1 = squared secant of x, 1 + squared cotangent of x = squared cosecant of x.

$\text{cos}^2 θ +\text{sin}^2 θ$

$1 − \text{cos}^2 θ$

$1 − \text{cos}^2 5$

$1 −\text{ sin}^2 β$

$1 −\text{ sin}^2 (3δ)$
Answer (e):
$\text{cos}^2(3δ)$

$4 − 4\text{ sin}^2 (3δ)$
Hint (f):
Factor out a $4$ first.