Question

14. Without using tables, verify that :
• (i) cos 60° = (cos^2 30° - sin^2 30°).
pls write the answer
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Answer 1

Answer: what you have written is a property

Step-by-step explatnion:

cos²x-sin²x=cos2x this is the property

now suppose x=30 you got the answer and the derivation for this is

cos(x+y)= cosxcosy - sinxsiny, put x and y=30