高三第一輪復(fù)習(xí)-函數(shù)的基本性質(zhì)

【學(xué)案編號】數(shù)學(xué)總復(fù)習(xí)【編輯】韓晶飛【審核】馬省珍主題函數(shù)的基本性質(zhì)學(xué)案5【】函數(shù)的基本性質(zhì)之一——單調(diào)性f(x)()()xxfxfxy1212xx，f(x)f(x)；1212f(x)fx()()yfx12f(x)f(x)。12f(x)當(dāng)y1.f(x)xx1,(0,)xxfx()()fx”21212）1(x)f(x)(x2f(x)exyln(x．fx12x②y(x③yx1④y2yx112x[0,)在y4x在[2,)yx(a2)x1,x1(x)()(,)若fx在aflogx,x1a1(x)f()f(1)f為Rx）x.()(()(x)(0,)f）33()f(aa1)f()f(aa1)Af224343()f(aa1)f()f(aa1)f22444,0xxx2(x)若f(2a)f(a)af）24xx,x02(,1)(2,)((,)(x)x2(a1)x2(,4]af2(x)x2(a1)x2(,4]在af2(x)x2ax2,x[1,1]f(x)f2(x)x2x2,x[t,t1],tRf(x)f2(x)12xtxt,xR0f(x)ft22B級1,02xx(x)f(1x)f(2x)的x11.f21,x0f(x)(,)內(nèi)有定義。對于給定的正數(shù)K，定義函數(shù)設(shè)函數(shù)y在f(x),f()K(x)2x12(x)f()fxKfK,f(x)KKK）((0,)(,D).a,,ca,b,c()min2,2,10(0)xx，用fxxx(x)則f）函數(shù)的基本性質(zhì)之二——奇偶性與周期性）(x)f(x)f(x)f(x)的關(guān)系：如果=，則函數(shù)為偶函數(shù)；如果）判斷f與(x)f(x)f(x)f==(x)fx(xT)f(x)f(x)Tfg(x)3f(x3()x的定義域均為R，則fx為若函數(shù)xx與xg(x)g(x)(x)f和R）(x)g(x)(x)g(x)f(x)g(x)．f．ff(x)g(x)x1234(x)f（(2x1)(xa)23f0）(x)x(b2)xf若21f(x)a21x(x)x0f(x)22xb（b設(shè)fRxf(1)(x)xxa2ff(x)g(x)f(x)9g(3f，f(a)(x)xsinx1f(a)2f3(x)10.Rf(0)f(x)）x1yx1．y2,0ex2x1,x0xyye,x0x31,x0x(x)x2x(x0)f(3a)f(2a)aRf221f(2x1)f()3(0,)的xxf(x2)=（）(x)f(x)24(x0)xfAxxxx或xx4Bxxx或x6xxf(x)f(x)(x)(0,)在f00f）x．((2,)(,(2,)(,2)(5(x)20x1f(x)2xx)f()設(shè)f設(shè)f2(x)f(1)1f2，ff是R5(x)x0f(xf(x)0x2f是R有f(x)log(x1)f(f2(x)xRf(x)fx)有f是Rf(x)f(xf(x)Rf（）(f(11)fff(11)f(f(fff(11)ff(f(x)f(xf(x與f）(x)f(x)．f(x)f(xf(x．f(x)x,yf(xy)f(x)f(y)x0f(x)0當(dāng)，f(x)f在R(x)(0,)f(xy)f(x)f(y)f1，f(a)f(a1)2且fa(x)x,yf(xy)