Respuesta :

Answer:

Step-by-step explanation:

cos A+secA=2

squaring

cos²A+sec²A+2cosA sec A=4

cos²A+sec²A+2cos A/cos A=4

cos²A+sec²A+2=4

cos²A+se²A=4-2=2

again squaring

cos^4A+sec^4A+2cos²Asec²A=4

cos^4A+sec^4A+2=4

cos^4A+sec^4A=4-2=2

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