Proving the Cofunction Identities
𝜋
a) Verify sin ( 2 − 𝜃) = 𝑐𝑜𝑠𝜃
𝜋
b) Verify cos ( 2 − 𝜃) = 𝑠𝑖𝑛𝜃
𝜋
c) Verify csc ( 2 − 𝜃) = 𝑠𝑒𝑐𝜃
Ex. 3 Verify the identity.
a) sin (𝜃 +
3𝜋
2
) = −𝑐𝑜𝑠𝜃
b) cos(360° − 𝜃) = 𝑐𝑜𝑠𝜃