arccot(2加上根号2加上根号3加上根号6),要用弧度制表示的值
arccot(2+√2+√3+√6)=
2+√2+√3+√6
=(2+√2)+(√3+√6)
=(√2+1)√2+(1+√2)√3
=(√2+1)(√2+√3)
=(1+√2)/(√3-√2)
=(0.5+0.5√2)/(0.5√3-0.5√2)
=[cos(π/3)+cos(π/4)]/[sin(π/3)-sin(π/4)]
=2cos(π/6+π/8)cos(π/6-π/8)
/[2cos(π/6+π/8)sin(π/6-π/8)]
=cos(π/6-π/8)/sin(π/6-π/8)
=cos(π/24)/sin(π/24)
=cot(π/24)
∴ arc cot(2+√2+√3+√6)=π/24
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