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1ãåä½ç§¯=4/3(pi)(r^3)
2ãé¢ç§¯=(pi)(r^2)
3ãå¨é¿=2(pi)r
4ãåçæ åæ¹ç¨(x-a)2+(y-b)2=r2ã(a,b)æ¯åå¿åæ ã
5ãåçä¸è¬æ¹ç¨x2+y2+dx+ey+f=0ãd2+e2-4f>0ã
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1ãsin(a+b)=sinacosb+cosasinbsin(a-b)=sinacosb-sinbcosa
2ãcos(a+b)=cosacosb-sinasinbcos(a-b)=cosacosb+sinasinb
3ãtan(a+b)=(tana+tanb)/(1-tanatanb)tan(a-b)=(tana-tanb)/(1+tanatanb)
4ãctg(a+b)=(ctgactgb-1)/(ctgb+ctga)ctg(a-b)=(ctgactgb+1)/(ctgb-ctga)
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1ãtan2a=2tana/(1-tan2a)ctg2a=(ctg2a-1)/2ctga
2ãcos2a=cos2a-sin2a=2cos2a-1=1-2sin2a