《初中数学公式大全》

1a2-b2=(a+b)(a-b)(a+b)2=a2+b2+2ab(a-b)2=a2+b2-2aba3+b3=(a+b)(a2-ab+b2)a3-b3=(a-b)(a2+ab+b2)|a+b||a|+|b||a-b||a|+|b||a|b=-ba|a-b||a|-|b|-|a|a|a|-b+(b2-4ac)/2a-b-b+(b2-4ac)/2aX1+X2=-b/aX1*X2=c/ab2-4a=0b2-4ac0b2-4ac0sin(A+B)=sinAcosB+cosAsinBsin(A-B)=sinAcosB-sinBcosAcos(A+B)=cosAcosB-sinAsinBcos(A-B)=cosAcosB+sinAsinBtan(A+B)=(tanA+tanB)/(1-tanAtanB)tan(A-B)=(tanA-tanB)/(1+tanAtanB)ctg(A+B)=(ctgActgB-1)/(ctgB+ctgA)ctg(A-B)=(ctgActgB+1)/(ctgB-ctgA)tan2A=2tanA/(1-tan2A)ctg2A=(ctg2A-1)/2ctgacos2a=cos2a-sin2a=2cos2a-1=1-2sin2asin(A/2)=((1-cosA)/2)sin(A/2)=-((1-cosA)/2)cos(A/2)=((1+cosA)/2)cos(A/2)=-((1+cosA)/2)tan(A/2)=((1-cosA)/((1+cosA))tan(A/2)=-((1-cosA)/((1+cosA))ctg(A/2)=((1+cosA)/((1-cosA))ctg(A/2)=-((1+cosA)/((1-cosA))2sinAcosB=sin(A+B)+sin(A-B)2cosAsinB=sin(A+B)-sin(A-B)2cosAcosB=cos(A+B)-sin(A-B)-2sinAsinB=cos(A+B)-cos(A-B)sinA+sinB=2sin((A+B)/2)cos((A-B)/2cosA+cosB=2cos((A+B)/2)sin((A-B)/2)tanA+tanB=sin(A+B)/cosAcosBtanA-tanB=sin(A-B)/cosAcosB2ctgA+ctgBsin(A+B)/sinAsinB-ctgA+ctgBsin(A+B)/sinAsinBn1+2+3+4+5+6+7+8+9+,+n=n(n+1)/21+3+5+7+9+11+13+15+,+(2n-1)=n22+4+6+8+10+12+14+,+(2n)=n(n+1)12+22+32+42+52+62+72+82+,+n2=n(n+1)(2n+1)/613+23+33+43+53+63+,n3=n2(n+1)2/41*2+2*3+3*4+4*5+5*6+6*7+,+n(n+1)=n(n+1)(n+2)/3a/sinA=b/sinB=c/sinC=2RRb2=a2+c2-2accosBBac(x-a)2+(y-b)2=r2a,bx2+y2+Dx+Ey+F=0D2+E2-4F0y2=2pxy2=-2pxx2=2pyx2=-2pyS=c*hS=c'*hS=1/2c*h'S=1/2(c+c')h'S=1/2(c+c')l=pi(R+r)lS=4pi*r2S=c*h=2pi*hS=1/2*c*l=pi*r*ll=a*r(ar0)s=1/2*l*rV=1/3*S*HV=1/3*pi*r2hV=s*hV=pi*r2hV=S'L(S'L)pi=3.14159265358979,,:a2-b2=(a+b)(a-b)a3+b3=(a+b)(a2-ab+b2)a3-b3=(a-b(a2+ab+b2)|a+b||a|+|b||a-b||a|+|b||a|b=-bab3|a-b||a|-|b|-|a|a|a|-b+(b2-4ac)/2a-b-(b2-4ac)/2aX1+X2=-b/aX1*X2=c/ab2-4ac=0b2-4ac0b2-4ac0sin(A+B)=sinAcosB+cosAsinBsin(A-B)=sinAcosB-sinBcosAcos(A+B)=cosAcosB-sinAsinBcos(A-B)=cosAcosB+sinAsinBtan(A+B)=(tanA+tanB)/(1-tanAtanB)tan(A-B)=(tanA-tanB)/(1+tanAtanB)ctg(A+B)=(ctgActgB-1)/(ctgB+ctgA)ctg(A-B)=(ctgActgB+1)/(ctgB-ctgA)tan2A=2tanA/(1-tan2A)ctg2A=(ctg2A-1)/2ctgacos2a=cos2a-sin2a=2cos2a-1=1-2sin2asin(A/2)=((1-cosA)/2)sin(A/2)=-((1-cosA)/2)cos(A/2)=((1+cosA)/2)cos(A/2)=-((1+cosA)/2)tan(A/2)=((1-cosA)/((1+cosA))tan(A/2)=-((1-cosA)/((1+cosA))ctg(A/2)=((1+cosA)/((1-cosA))ctg(A/2)=-((1+cosA)/((1-cosA))2sinAcosB=sin(A+B)+sin(A-B)2cosAsinB=sin(A+B)-sin(A-B)2cosAcosB=cos(A+B)-sin(A-B)-2sinAsinB=cos(A+B)-cos(A-B)sinA+sinB=2sin((A+B)/2)cos((A-B)/2cosA+cosB=2cos((A+B)/2)sin((A-B)/2)tanA+tanB=sin(A+B)/cosAcosBtanA-tanB=sin(A-B)/cosAcosBctgA+ctgBsin(A+B)/sinAsinB-ctgA+ctgBsin(A+B)/sinAsinB4n1+2+3+4+5+6+7+8+9++n=n(n+1)/21+3+5+7+9+11+13+15++(2n-1)=n22+4+6+8+10+12+14++(2n)=n(n+1)12+22+32+42+52+62+72+82++n2=n(n+1)(2n+1)/613+23+33+43+53+63+n3=n2(n+1)2/41*2+2*3+3*4+4*5+5*6+6*7++n(n+1)=n(n+1)(n+2)/3a/sinA=b/sinB=c/sinC=2RRb2=a2+c2-2accosBBac(x-a)2+(y-b)2=r2a,bx2+y2+Dx+Ey+F=0D2+E2-4F0y2=2pxy2=-2pxx2=2pyx2=-2pyS=c*hS=c'*hS=1/2c*h'S=1/2(c+c')h'S=1/2(c+c')l=pi(R+r)lS=4pi*r2S=c*h=2pi*hS=1/2*c*l=pi*r*ll=a*rar0s=1/2*l*rV=1/3*S*HV=1/3*pi*r2hV=S'L,S'LV=s*hV=pi*r2hA1/0//000//000050010NAAN2XAXAXAXA2/00/AAXAXA/00/AA3L(1)2vts(3)s=FW(4)1l=122.FlF5gph(6)h=SVa=3VKmmdmcmmm1km=1000m1m=100cmS(1)SabS=a2S=R2=41D2(2)hVs(3)Fps1m2=102dm21dm2=102cm21cm2=102mm2V(1)V=a3V=Sh=abhVShV34R3(2)mV(3)V=V2V1(4)VVF/gVVV1m3=103dm31dm3=103cm31cm3=103mm3t1vst2PWt31h=60min1min=60sv1tsv2FvtFstWPFPv1m/s=3.6km/hm(1)gGm21t=1000kg1kg=1000g1g=1000mg6mghGhWghWm(3)Vm4(1)VmgGmgVG(2)ghpghp(3)FgVgVF1g/cm3=1000kg/m3F(1)F=F1F22F=F1F2F1F2Np(1)SFp2ghp1Pa=1N/m2F(1)FGF(2)FFF(3)FgV(4)FG2211lFlF1221llFF2112llFF1l2lW(1)W=FsW=Gh=mghW=fs(2)W=Fs(3)==WW=W4tWPW=Pt1J=1N.m=1w.s(1)=WW=(2)=WW=PPtPtP(3)=nFGn(4)=WW=GGGhGGhGh17F(1)FGn12)(1GGnF3nGFn4Ff(f)(P)(1)P=tW(2)P=tW=FvtFs(3)1w=1J/s=1N.m/sc(1)Qcm(tt0)Qcm(t0t)Q=cmttmQc(2)QqmqJ/kgmkg(3)QqV(qJ/m3Vm3)(4)QQCJ/(Kg.),4.2103J/Kg.1kg14.2103JQ(1)tQIQIt(2)W=UIt=UQQUWQQCI(1)tQIQ2RUI3W=UItUtWI(4)PUIUPIP(5)QI2RtRtQI(6)W=UItI2RtRtWI(7)PUII2RRPI(8)II1I2II1I291A=1000mAU(1)QWUQ2UIR3ItWU4IPU1KV=1000V,1V=1000mV220V36V8(5)tQRUtRUQ2QRUP2PRU(6)UU1U2UU1U27R(1)IUR()2WUItI2RttRU2WtURtIWR22322IPRRIPPURRUP22(4)QI2RtQtURtIQR22Q(5)RR1R2R1RR2R2RR1(6)21111RRR2121RRRRR7101A11V/A1M=1061K=103W(1)WUItUQQ2WQtRURtI223PtWWPt4WQRtI25KWhJKW.h1KW.h=3.6106JP(1)RURIUIP22(2)PtW(3)1Kw=1000w1735wQ(1)tRURtIQ22QWRtI2(2)QQJt(1)IQt(Q)(2)WUItUIWt(3)PtWPWt(4)QRtI2RIQt2