Question

cos^2 25° + cos^2 65º = 1
Please help me ​

Answer 1

Answer:

here your answer

Step-by-step explanation:

Answer 2

Step-by-step explanation:

to prove cos² 25° + cos²65° = 1

LHS : We know that cos²(90 - A)= sin²A

therefore cos²25° + cos²65° => cos²25° + cos²(90° - 25°)

=> cos²25° + sin²25°

=> 1 [ cos²X + sin²X ] = 1

LHS = RHS hence proved