Question

what is the value of cos sqr67degree -sin square23degree
I'll mark it as a brainliest and.

Answer 1

Hi ,

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We know that ,

Sin( 90 - A ) = cosA

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Now ,

Cos² 67° - sin² 23°

= cos² 67° - sin² ( 90 - 67°)

= cos² 67° - cos² 67°

= 0

I hope this helps you.

: )

Answer 2

cos^267 -sin^2-23

my friend ,for answering this question we need to know some formulas ,
cosФ=sin(90-Ф)
tanФ=cot(90-Ф)
secФ=cosec(90-Ф)

therefore after knowing this formula ,we can easily move on with the sum ,
=cos^2 67-sin ^2(90-67)
=cos^2 67-cos^2 67 
=0 is the answer