Diagnostische Toets Wis B VWO Hoofdstuk 5 Exponenten en logaritmen Getal en Ruimte wiskunde uitwerkingen www.uitwerkingensite.nl SCROLL DOWN || || V 5.5 Diagnostische toets bladzijde 48 1 a y = 3x ↓ translatie (2, -3) f (x) = 3x-2 - 3 y= () 1 3 x ↓ verm. x-as, 4 y = 4⋅ () 1 3 x ↓ translatie (0, - 6) () g x = 4⋅ () 1 3 x -6 32Hoofdstuk5 224968 H5.indd 32 01-11-2007 09:54:13 b Voer in y1 = 3x-2 - 3 en y2 = 4 ⋅ () 1 3 x - 6. x -1 0 1 2 3 4 f (x) -3,0 -2,9 -2,7 -2 0 6 g(x) 6 -2 - 4,7 -5,6 -5,9 - 6,0 y y=6 6 5 4 3 ƒ 2 g 1 0,22 –1 O 1 2 3 x –1 –2 y = –3 –3 –4 –5 y = –6 –6 c Bf = 〈-3, →〉 en Bg = 〈- 6, →〉 d De optie intersect geeft x ≈ 0,22. f (x) ≥ g(x) geeft x ≥ 0,22. ( ) -6 = 6 4 ⋅ ( ) = 12 ( ) =3 ( ) =( ) e g(x) = 6 geeft 4 ⋅ 1 3 1 3 1 3 1 3 x x x x 1 3 -1 x = -1 g(x) ≤ 6 geeft x ≥ -1 f f (4) = 6 Voor x ≤ 4 is -3 < f (x) ≤ 6. Exponentenenlogaritmen33 224968 H5.indd 33 01-11-2007 09:54:14 2 c 2 ⋅ 42 x -1 - 3 = 6611 a 5x−1 = 125⋅ 3 5 1 3 2 ⋅ 42 x -1 = 64 64 5x-1 = 53 ⋅ 5 1 3 3 42 x -1 = 32 32 5x-1 = 5 (2 ) x - 1 = 3 1 3 2 1 27 = 1 2 x-5 3 33 3 1 ⋅ 32 1 3 2 x-5 = 3-3 ⋅ 32 d 1 3 2 x-5 = 3-2 2 ( ) = 33 x+1 3 =3 2x - 2 = 3x + 3 -x = 5 x = -5 b 2x+2 + 2x-1 = 36 2x ⋅ 22 + 2x ⋅ 2-1 = 36 2x-2 3x+3 = = 1 8 () 1 2 () =( ) d 2x = 2 2x 3 2 1 8 x 1 x 2 3 ( ) x x 4 ⋅ 2 x + 12 ⋅ 2 x = 36 2 x = 2 -3 4 12 ⋅ 2 x = 36 2 x = 22 -33xx x2 = -33x x2 + 3x = 0 x(x + 3) = 0 x=0 ∨ x=-33 2 2 2x = 8 2x = 23 x = 3 4 3 x +1 c 3x + 1 = 3x + 54 54 3 ⋅ 3x = 3x + 54 54 2 ⋅ 3x = 54 54 3x = 27 27 3x = 33 x = 3 a 9x-1 = 27x+1 2 3 x +11 + 6 = 66 8 81 3x + 1 = 3 3x = 2 x = 23 x = 1 1 4 (3 ) 3 x +11 1 2 1 2 2x = 2 1 2 x-1 ( ) () () 1 2 2x - 5 = -2 1 2 3 = 2 25 24 x - 2 = 22 5 4x - 2 = 5 4x = 7 x = 1 43 x = 4 1 3 b 3 2 x−5 = 2 x -1 a Stel H = b ⋅ gt. 7 gdag = 1+ 100 = 1, 07 Op t = 0 is H = 20, dus b = 20. Dus H = 20 ⋅ 1,07t. b Voer in y1 = 20 ⋅ 1,07x en y2 = 55. De optie intersect geeft x ≈ 14,95. Hierbij hoort 15 mei. c t H 18 67,60 19 72,33 20 77,39 + 4,73 + 5,06 Dus op 20 mei. 5 a gdag = 1,10, dus gweek = 1,107 ≈ 1,949. Het groeipercentage per week is 94,9. 1 b g8 uur = 1,10 3 ≈ 1, 032 Het groeipercentage per 8 uur is 3,2. 6 1 a gjaar = 0,64, dus gmaand = 0, 6412 ≈ 0, 963 De afname per maand is 3,7%. b g5jaar = 0,645 ≈ 0,107. De afname per 5 jaar is 89,3%. 34Hoofdstuk5 224968 H5.indd 34 01-11-2007 09:54:23 7 1200 = 0, 8. 1500 g3 dagen = 1 gdag = 0, 8 3 ≈ 0, 928. N = b ⋅ 0,928t voor t = 4 is N = 1500 } 1500 = b ⋅ 0,9284 1500 =b 0, 9284 b ≈ 2020 Dus N = 2020 ⋅ 0,928t. ( ) ( ) ( ) log ( ⋅ 2 ) = log ( 2 ⋅ 2 ) = log ( 2 ) = −3 1 1 8 a 3 log 3 3 = 3log 31 ⋅ 32 = 3log 3 2 = 1 12 b c 2 1 3 1 16 log d 2 log −4 2 3 1 1 3 2 −3 3 2 () 1 3 = 0, 6 1 1 ⎛ 1 ⎞ 1 − 8 = 2 log ⎜ 2 ⋅ 23 ⎟ = 2 log 2 −2 ⋅ 2 2 = 2 log 2 2 = − 12 ⎝2 ⎠ 0 ,6 ) ( ( ) 1 4 2 3 ( ) bladzijde 49 9 a 4log(2x - 3) = 2 2x - 3 = 42 2x - 3 = 16 2x = 19 x = 9 12 b 3 + 3log(x) = 7 3 log(x) = 4 x = 34 x = 81 c 1 2 log(xx - 33)) = - 4 log( 4 x-3= () 1 2 -4 ( ) x - 3 = 2 -1 -4 x - 3 = 24 x - 3 = 16 x = 19 d 5 + 3 ⋅ 2log( log(xx) = 20 3 ⋅ 2log( log(xx) = 15 2 log(xx) = 5 log( x = 25 x = 32 log(20) ≈ 21, 61 log( 2) 6 6 b 3 = ≈ 1, 94 log(30) log(30) log(3) a 2x + 5 > 0 geeft 2x > -5 x > -2 12 10 a 5⋅ 2 log(20) = 5⋅ 11 Dus Df = 〈-2 12 , →〉 en de verticale asymptoot is de lijn x = -2 12 . x -2 -1 0 1 2 3 6 f (x) 3 1,4 0,7 0,2 - 0,2 - 0,5 -1,1 y 3 ƒ 2 1 x= 1 –22 –2 –1 O 1 3 4 5 x Exponentenenlogaritmen35 224968 H5.indd 35 01-11-2007 09:54:28 b f (x) = -2 geeft 3 - 2log(2x + 5) = -2 -2log(2x + 5) = -5 2 log(2x + 5) = 5 2x + 5 = 25 2x + 5 = 32 2x = 27 x = 13 12 f (x) ≥ -2 geeft -2 12 < x ≤ 13 12 . c f 5 1 2 = 3 - 2log(11 + 5) = 3 - 2log(16) = 3 - 4 = -1 Voor x ≤ 5 12 is f (x) ≥ -1. ( ) 12 a Df = 〈-1, →〉 en de verticale asymptoot is de lijn x = -1. -x + 6 > 0 geeft -x > - 6 x<6 Dg = 〈←, 6〉 en de verticale asymptoot is de lijn x = 6. x - 43 - 12 0 1 3 7 f (x) 2 1 0 -1 -2 -3 x -2 2 4 5 5 12 5 43 5 78 g(x) 3 2 1 0 -1 -2 -3 y 4 3 g 2 1 –2 O –1 1 2 3 4 5 6 x –1 ƒ –2 –3 x = –1 –4 x=6 1 b f (x) = 4 geeft 2 log(x + 1) = 4 x +1 = () 1 2 4 x + 1 = 161 15 x = - 16 c g(-2) = log(2 + 6) = 2log(8) = 3 Voor x ≥ -2 is g(x) ≤ 3. 2 1 d f (x) = 2 geeft 2 log(x + 1) = 2 x +1 = () x +1 = 1 4 x=- 1 2 2 3 4 1 f (x) = -2 geeft 2 log(x + 1) = -2 x +1 = () 1 2 -2 x + 1 = 4 x = 3 -2 ≤ f (x) ≤ 2 geeft - 43 ≤ x ≤ 3 36Hoofdstuk5 224968 H5.indd 36 01-11-2007 09:54:31 e Voer in y1 = ( ) log x + 1 log () 1 2 en y2 = ( log - x + 6 () log 2 ). De optie intersect geeft x ≈ - 0,85 en x ≈ 5,85 f (x) ≤ g(x) geeft - 0,85 ≤ x ≤ 5,85. 1 f f (x) = 1 geeft 2 log(x + 1) = 1 x +1 = 1 2 x = - 12 ( ) g (x) = 1 geeft 2log(-x + 6) = 1 -x + 6 = 2 -x = - 4 x=4 Dus AB = 4 - - 12 = 4 12 . I 13 LJan = 78 geeft 10 log Jan = 78 I 0 I log Jan = 7, 8 I0 I Jan = 107 ,8 10 -12 IJan = 10- 4,2 W/m2 I LFrits = 80 geeft 10 log Frits = 80 I0 I log Frits = 8 I0 I Frits = 108 10 -12 IFrits = 10- 4 W/m2 I LGerrit = 81 geeft 10 log Gerrit = 81 I0 I log Gerrit = 8,1 I 0 I Gerrit = 108,1 10 -12 IGerrit = 10-3,9 W/m2 Itotaal = 10- 4,2 + 10- 4 + 10-3,9 W/m2 10 - 4,2 + 10 - 4 + 10 -3,9 Ltotaal = 10 log ≈ 85 dB 10 -12 Het geluidsniveau van de drie brommers samen is 85 dB. Exponentenenlogaritmen37 224968 H5.indd 37 01-11-2007 09:54:35 N 103 2 3 4 5 6 7 8 9104 2 3 4 5 6 7 8 9105 14 a 1990 1993 1995 1999 2001 2004 2005 2005 jaar jaar b Rechte lijn op logaritmisch papier dus N = b ⋅ g . t Lijn door (0, 15 000) en (15, 4300), dus g15 jaar = 1 15 4300 gjaar = ≈ 0, 920 15000 4300 . 15000 Op t = 0 is N = 15 000, dus b = 15 000. Dus N = 15 000 ⋅ 0,920t. 15 a Rechte lijn op logaritmisch papier dus NI = b ⋅ gt. 1 500 2 ≈ 1, 291. Lijn door (1, 300) en (3, 500), dus g = 300 t NI = b ⋅ 1,291 . 300 = b ⋅ 1,291 voor t = 1 is NI = 300 300 =b 1, 291 b ≈ 230 } Dus NI = 230 ⋅ 1,291t. b Rechte lijn op logaritmisch papier dus NII = b ⋅ gt. 1 400 2 Lijn door (1, 700) en (3, 400), dus g = ≈ 0, 756. 700 NII = b ⋅ 0,756t 700 = b ⋅ 0,756 voor t = 1 is NII = 700 700 =b 0, 756 b ≈ 930 } Dus NII = 930 ⋅ 0,756t. 38Hoofdstuk5 224968 H5.indd 38 01-11-2007 09:54:36 16 a gmaand = 1,002 1,002T = 2 T = 1,002 log( 2) = log( 2) ≈ 347 maanden ≈ 29 jaar log(1, 002) Dus de verdubbelingstijd is 29 jaar. b gweek = 0,8 0, 8T = 1 2 T = 0,8log () 1 2 = log ( ) ≈ 3,1 weken ≈ 22 dagen. 1 2 ( ) log 0, 8 De halveringstijd is 22 dagen. 17 g32 dagen = gdag = () 1 2 1 2 1 32 ≈ 0, 979 De afname is 2,1% per dag. Exponentenenlogaritmen39 224968 H5.indd 39 01-11-2007 09:54:36
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