Wiki-Quellcode von Lösung Ermittlung der Funktionsgleichung
Zuletzt geändert von Simone Hochrein am 2026/02/03 14:25
Verstecke letzte Bearbeiter
| author | version | line-number | content |
|---|---|---|---|
| |
1.1 | 1 | (%class=abc%) |
| 2 | 1. ((({{formula}} a=4, \quad P(2,5 | 14), \quad f(x)=c \cdot a^{x} {{/formula}} | ||
| 3 | |||
| 4 | {{formula}}f(x)=c \cdot 4^x {{/formula}} | ||
| 5 | |||
| 6 | {{formula}} | ||
| 7 | \begin{aligned} | ||
| 8 | f(2,5) &= 4 \\ | ||
| 9 | 4 &= c \cdot 4^{2,5} && | : 4^{2,5} \\ | ||
| 10 | c &= \frac{4}{4^{2,5}} = 0,125 \\ | ||
| 11 | \end{aligned} | ||
| 12 | {{/formula}} | ||
| 13 | |||
| |
2.1 | 14 | {{formula}}\Rightarrow f(x)= 0,125 \cdot 4^{x} {{/formula}} |
| |
1.1 | 15 | ))) |
| 16 | 1. ((({{formula}} c=6, \quad P(-1 | 9), \quad f(x)=c \cdot a^{x} {{/formula}} | ||
| 17 | |||
| 18 | {{formula}}f(x)=6 \cdot a^x {{/formula}} | ||
| 19 | |||
| 20 | {{formula}} | ||
| 21 | \begin{aligned} | ||
| 22 | f(-1) &= 9 \\ | ||
| 23 | 9 &= 6 \cdot a^{-1} \\ | ||
| 24 | 9 &= \frac{6}{a} && | \cdot a \quad | : 9 \\ | ||
| 25 | a &= \frac{6}{9} = \frac{2}{3} \\ | ||
| 26 | \end{aligned} | ||
| 27 | {{/formula}} | ||
| 28 | |||
| |
2.1 | 29 | {{formula}}\Rightarrow f(x)= 6 \cdot \left(\frac{2}{3}\right)^{x} {{/formula}}))) |
| |
1.1 | 30 | 1. ((({{formula}} A(0 | -2), \quad B(2 | -4,5), \quad f(x)=c \cdot a^{x} {{/formula}} |
| 31 | |||
| 32 | {{formula}} | ||
| 33 | \begin{aligned} | ||
| 34 | f(0) &= -2 \Rightarrow -2 = c \cdot a^{0} \Rightarrow c = -2 \\ | ||
| 35 | f(x) &= -2 \cdot a^{x} \\ | ||
| 36 | f(2) &= -4,5 \\ | ||
| 37 | -4,5 &= -2 \cdot a^{2} && | : (-2) \\ | ||
| 38 | 2,25 &= a^{2} && | \sqrt{\phantom{x}} \\ | ||
| 39 | a &= 1,5 \\ | ||
| 40 | \end{aligned} | ||
| 41 | {{/formula}} | ||
| 42 | |||
| |
2.1 | 43 | {{formula}}\Rightarrow f(x)= -2 \cdot 1,5^{x} {{/formula}}))) |
| |
1.1 | 44 | 1. ((({{formula}} A(1 | 1,5), \quad B(2 | 4,5), \quad f(x)=c \cdot a^{x} {{/formula}} |
| 45 | |||
| 46 | {{formula}} | ||
| 47 | \begin{aligned} | ||
| 48 | 1,5 &= c \cdot a && (1) \\ | ||
| 49 | 4,5 &= c \cdot a^{2} && (2) \\ | ||
| 50 | \text{aus (1): } c &= \frac{1,5}{a} && (3) \\ | ||
| 51 | \text{(3) in (2): } 4,5 &= \frac{1,5}{a} \cdot a^{2} \\ | ||
| 52 | 4,5 &= 1,5 \cdot a && | : 1,5 \\ | ||
| 53 | a &= 3 && (4) \\ | ||
| 54 | \text{(4) in (3): } c &= \frac{1,5}{3} = 0,5 \\ | ||
| 55 | \end{aligned} | ||
| 56 | {{/formula}} | ||
| 57 | |||
| 58 | {{formula}}\Rightarrow f(x)= 0,5 \cdot 3^{x} {{/formula}}))) | ||
| 59 | 1. ((({{formula}} A(2 | 1), \quad B(5 | 27), \quad f(x)=c \cdot a^{x} {{/formula}} | ||
| 60 | |||
| 61 | {{formula}} | ||
| 62 | \begin{aligned} | ||
| 63 | 1 &= c \cdot a^{2} && (1) \\ | ||
| 64 | 27 &= c \cdot a^{5} && (2) \\ | ||
| 65 | \text{aus (1): } c &= \frac{1}{a^{2}} && (3) \\ | ||
| 66 | \text{(3) in (2): } 27 &= \frac{1}{a^{2}} \cdot a^{5} \\ | ||
| 67 | 27 &= a^{3} && | \sqrt[3]{\phantom{x}} \\ | ||
| 68 | a &= 3 && (4) \\ | ||
| 69 | \text{(4) in (3): } c &= \frac{1}{3^{2}} = \frac{1}{9} \\ | ||
| 70 | \end{aligned} | ||
| 71 | {{/formula}} | ||
| 72 | |||
| 73 | {{formula}}\Rightarrow f(x)= \frac{1}{9} \cdot 3^{x} {{/formula}}))) | ||
| 74 | 1. ((({{formula}} A(2 | 16), \quad B(-2 | \frac{81}{16}), \quad f(x)=c \cdot a^{x} {{/formula}} | ||
| 75 | |||
| 76 | {{formula}} | ||
| 77 | \begin{aligned} | ||
| 78 | 16 &= c \cdot a^{2} && (1) \\ | ||
| 79 | \frac{81}{16} &= c \cdot a^{-2} && (2) \\ | ||
| 80 | \text{aus (1): } c &= \frac{16}{a^{2}} && (3) \\ | ||
| 81 | \text{(3) in (2): } \frac{81}{16} &= \frac{16}{a^{2}} \cdot a^{-2} \\ | ||
| 82 | \frac{81}{16} &= \frac{16}{a^{2}} \cdot \frac{1}{a^{2}} \\ | ||
| 83 | \frac{81}{16} &= \frac{16}{a^{4}} && | \text{ Kehrwert} \\ | ||
| 84 | \frac{16}{81} &= \frac{a^{4}}{16} && | \cdot 16 \\ | ||
| 85 | a^{4} &= \frac{256}{81} && | \sqrt[4]{\phantom{x}} \\ | ||
| 86 | a &= \frac{4}{3} && (4) \\ | ||
| 87 | \text{(4) in (3): } c &= \frac{16}{(4/3)^{2}} = 9 \\ | ||
| 88 | \end{aligned} | ||
| 89 | {{/formula}} | ||
| 90 | |||
| |
2.1 | 91 | {{formula}}\Rightarrow f(x)= 9 \cdot \left(\frac{4}{3}\right)^{x} {{/formula}}))) |
| |
1.1 | 92 |