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# 高2020届高2017级高中数学文科数学第一轮复习状元桥全套课练习第2章 第11讲

11 1. f(x)x32x1 ( ) A.(0,1) B.(1,2) C.(2,3) D.(3,4) A f(0)1<0,f(1)2>0, f(0)f(1)2<0, f(x)x32x1 , f(x)(0,1). 2. f(x)2x3x7 [0,4], 2, ( ) A.(0,1) B.(0,2) C.(2,3) D.(2,4) B f(0)20076<0,f(4)24127>0, f(2)2267>0, f(0)f(2)<0,(0,2). B. 3.f(x)2sin xx1 ( ) A.4 B.5 C.6 D.7 B f(x)2sin xx10, 2sin xx1, h(x)2sin x,g(x)x1, f(x) 2sin xx1 h(x) g(x).h(x)2sin x 2,,,, 5 , f(x)2sin xx1 5. 4.(2019) f(x)x22x4xx12x1 g(x)f(x)x () A.0 B.1,2 C.1,0 D.2,1,0 B x1 ,g(x)f(x)x0, 2xx0. x1,; x1 ,g(x)f(x)xx23x20, x11 x22., g(x)1,2. 5.(2019) f(x)ex2x4,g(x)ln x2x25, a,b f(x),g(x) ,( ) A.g(a)0f(b) B.f(b)0g(a) C.0g(a)f(b) D.f(b)g(a)0 A ,f(0)30,f(1)e20, f(x), f(x) a (0,1),g(1)30,g(2)ln 230, g(x)(0,), g(x) b(1,2), f(b)f(1)0,g(a)g(1)0,g(a)0f(b). A. 6.(2017) f(x)x22xa(ex1ex1), a( ) A.12 1 B.3 1 C.2 D.1 C f(x)x22xa(ex1ex1)(x1)2a[ex1e(x1)]1, tx1, g(t) f(t1)t2a(etet)1. g(t)(t)2a(etet)1g(t), g(t). f(x), g(t). g(t), g(0)0, 2a 10, a12. C. 7. f(x)x22ax4 (1,), a ________. >0 22a>1 f1>0 4a216>0 a>1 a<52 5 2<a<2. 252 8. R f(x) x>0 ,f(x)2 019xlog2 019x, R , f(x) ________. f(x) R , f(0)0, x>0 ,f(x)2 019xlog2 019x 02 0119, f(x),(0,). (,0), f(x) R 3. 3 9.(2018) R,f(x)xx 244xx3x 2 , f(x)0 ________; f(x) 2 , ________. (1) 2 ,f(x)xx244xx32x2 (1). f(x)0 (1,4). (1) (2) (2)f(x)xx 244xx3x 2 , ;. yx4 y x24x3 ,(2), x, (1,3](4,). (1,4) (1,3](4,) 10. x x2(m1)x10 [0,2], m . x2(m1)x10 x0 . x(0,2],(m1)xx21,1 mx1x. x(0,2],x1x2, x1 ,, 1m2, m1, m (,1]. 11. f(x)ax2bxb1(a0). (1) a1,b2 , f(x); (2) bR, f(x), a . (1) a1,b2 ,f(x)x22x3, f(x)0, x3 x1. f(x) 3 1. (2),f(x)ax2bxb10 , b24a(b1)>0 a0, bR,b24ab4a>0 ,(4a)24(4a)<0a2a<0, 0<a<1, a (0,1). 12.(2019) f(x)ax2bxc(a0), f(0)2,f(x1)f(x)2x 1. (1) f(x); (2) x[1,2],; (3) g(x)f(x)mx (1,2)(2,4), m . (1) f(0) 2 c 2, f(x 1) f(x) 2x 1, 2ax a b 2x 1, 2a2 ab1 a1,b2, f(x)x22x2. (2)f(x)x22x2(x1)21, x1[1,2], f(x)minf(1)1, f(1) 5,f(2)2, f(x)maxf(1)5. (3)g(x) x2 (2 m)x 2, g(x) ( 1,2) (2,4) , g10 g20 g40 5m0 22m0 104m0 1m52. m 152. 13.[] yf(x) R ,f(x);f(x2); 0x2 ,f(x)log2 019x, x0 ,f(x)0, f(x)2 019 (1,10) ( ) A.0 B.10 C.12 D.24 D f(x2) f(x2)f(x2), f(x) x2 . f(x) , f(x) x0 , x2n(nZ) f(x). 0x2 ,f(x)log2 019x, x0 ,f(x)0,(1,10), f(x)2 019 4 , x 4 8, x8 16, f(x)2 019 (1,10) 24.

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