find

What is the value of cot 142.5

1 Answers

=cot(120+22.5)
we know cot 120=-1/âˆš3

and let tan22.5=x

then tan45=2x/1-x²

so we get tan22.5=

âˆš2-1
cot22.5=1/(âˆš2-1)=âˆš2+1
just put the formula

cot(A+B)=(cotAcotB-1)/(cotA+cotB)

√ √ || {} [] () → ~ ^ x x x → → ln log lg lim lim cos sin tan cot arcsin arccos arctan

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