Question

Sin 72 degree + cos 18 degrees sin 72 deg
ree minus cos 18 degree rate​

Answer 1

Answer:

(sin72°+cos18°)(sin72°-cos18°)=0

Step-by-step explanation:

(a+b)(a-b)

(a^2-b^2)

(sin^2 72°-cos^ 18°)

(sin^2 72°-cos^2 (90°-72°))

(sin^2 72°-sin^2 72°). [cos(90-theta)=sin theta]

0