Question

cos 30 – sin 30 =(cos 0 +sin )(1-2 sin 20)
show that
​

Answer 1

Answer:

Step-by-step explanation:

please mark me as a brilliant

cos(20°+θ)=sin30°

⇒cos(20°+θ)=cos(90°−30°)

⇒20°+θ=60°

⇒θ=40°

Hence, the answer is 40°.