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
