if cosx+secx=2 then the value of cos^100x-sec^100x=
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cosx+secx=2
cosx+1/cosx=2
cos²x+1=2cosx
cos²x-2cosx+1=0
D=√b²-4ac
a=1,b=-2,c=1
D=√-2²-4×1×1=√4-4=0
it means root are real and equal
cosx=(-b+D)/2a
=-(-2)+-0/2
=2/2=1
cosx=1
cosx=cos0
x=0
now,cos^100x-sec^100x=cos^100 0-sec^100 0=1-1=0
cosx+1/cosx=2
cos²x+1=2cosx
cos²x-2cosx+1=0
D=√b²-4ac
a=1,b=-2,c=1
D=√-2²-4×1×1=√4-4=0
it means root are real and equal
cosx=(-b+D)/2a
=-(-2)+-0/2
=2/2=1
cosx=1
cosx=cos0
x=0
now,cos^100x-sec^100x=cos^100 0-sec^100 0=1-1=0
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