If tan²A = 1+ 2tan²B Show: COS2B = 1+2 cos2A​

Question

If tan²A = 1+ 2tan²B
Show: COS2B = 1+2 cos2A​

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Amara 1 week 2021-09-12T10:42:41+00:00 1 Answer 0

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    2021-09-12T10:44:10+00:00

    Answer:

    Step-by-step explanation:

    hello :

    here is this idea :  

    tanA= sinA/cosA          tanB= sinB/cosB

    cos²A+sin²A =1              cos²B+sin²B =1  

    cos²A-sin²A=cos2A            cos²B-sin²B=cos2B

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