Question

Please explain how third step came with pic or by step by step explanation especially how 1-cos becomes 2sin^2theta/2​

Answer 1

Answer:

hope this helps

Step-by-step explanation:

cos2A=1-2sin²A

2sin²A=1-cos2A

Substitute A as thetha/2

You will get

1-cos(2thetha)=2sin²(thetha/2)