diff --git a/notes/.obsidian/graph.json b/notes/.obsidian/graph.json index 336851d..e2ddce9 100644 --- a/notes/.obsidian/graph.json +++ b/notes/.obsidian/graph.json @@ -95,6 +95,6 @@ "repelStrength": 10.2352941176471, "linkStrength": 0.458823529411765, "linkDistance": 240, - "scale": 0.3138188640425465, + "scale": 0.22383929542959702, "close": true } \ No newline at end of file diff --git a/notes/.obsidian/plugins/obsidian-activity-history/data.json b/notes/.obsidian/plugins/obsidian-activity-history/data.json index 2aa72ae..697507b 100644 --- a/notes/.obsidian/plugins/obsidian-activity-history/data.json +++ b/notes/.obsidian/plugins/obsidian-activity-history/data.json @@ -12,8 +12,8 @@ "checkpointList": [ { "path": "/", - "date": "2022-02-21", - "size": 780658 + "date": "2022-02-23", + "size": 780770 } ], "activityHistory": [ @@ -54,7 +54,15 @@ }, { "date": "2022-02-21", - "value": 1528 + "value": 1572 + }, + { + "date": "2022-02-22", + "value": 0 + }, + { + "date": "2022-02-23", + "value": 170 } ] } diff --git a/notes/mat/Absolutní hodnota.md b/notes/mat/Absolutní hodnota.md index a87e8f6..6cbf6c6 100644 --- a/notes/mat/Absolutní hodnota.md +++ b/notes/mat/Absolutní hodnota.md @@ -39,3 +39,7 @@ $-x=66$ $x=66$ ❌ $[66\not\in x<3]$ $x \geq 3$ +--- +$$\textcolor{red}{|x+1|}+\textcolor{green}{|x-1|}=4$$ +$\textcolor{red}{nulový \space bod \dots -1}$ $\textcolor{green}{nulový \space bod \dots 1}$ + diff --git a/notes/mat/Funkce/Příklady.md b/notes/mat/Funkce/Příklady.md index e69de29..64fe21d 100644 --- a/notes/mat/Funkce/Příklady.md +++ b/notes/mat/Funkce/Příklady.md @@ -0,0 +1,312 @@ +--- +Date: 2022-03-02 +--- +# Příklady + +## Určete definiční obory funkcí +--- +$f_1: y = x^3 - x^2 + 1$ +$D_{f_1} = \mathbb{R}$ + +--- +$f_2:y=\frac1{6-4x}$ +$D_{f_2} = \mathbb{R} - \{1.5\}$ + +--- +$f_3:y=\frac1{4x^2-9}$ +$D_{f_3} = \mathbb{R} - \{1.5\}$ + +--- +$f_4: y = \frac{\sqrt{4-2x}}3$ +$D_{f_4} = (-\infty; 2\rangle$ + +--- +$f_5:y=\sqrt{x-2}+\frac1x$ +$D_{f_5}=\langle2;\infty) - \{0\}$ + +--- +$f_6:y=\frac{\sqrt{x+3}}{\sqrt{x+7}}$ +$D_{f_6} = \langle-3;\infty) - \{-7\}$ + +--- +$f_7:y=\sqrt\frac{x+3}{x+7}$ +$D_{f_7} = \langle-3;\infty)$ + +--- +## Rozhodněte, zda číslo $d$ náleží $H(f_i)$ +--- +$d=7$ +$f_1:y=3x-4$ +$f_1^{-1}: x=\frac{y+4}3$ +$D_{f_1^{-1}}=\mathbb{R}$ +$H_{f_1}=\mathbb{R}$ +$7\in\mathbb{R}$ +✔️ + +--- +$d=5$ +$f_2:y=-5$ +$H_{f_2} = \{-5\}$ +$5 \not\in \{-5\}$ +❌ + +--- +$d=0$ +$f_3:y=\frac1{x+3}$ +$f_3^{-1} : x=\frac1y-3$ +$D_{f_3^{-1}} = \mathbb{R} - \{0\}$ +$0\not\in\mathbb{R}-\{0\}$ +❌ + +--- +$d=-4$ +$f_4:y=\frac{x+1}{x-2}$ +$f_4^{-1}:2=\frac1y$ +$y = \frac{x+1}{x-2}$ +$y(x-2)=x+1$ +$y(x-2)-x=1$ +$x-2=\frac{(1+x)}y$ + + +--- +$d=\frac12$ +$f_5:y=\frac1{x^2-1}$ +$f_5^{-1}: x=\sqrt{\frac1y+1}$ +$D_{f_5^{-1}} = H_{F_5} = (-1;\infty)$ +$\frac12 \in (-1; \infty)$ +✔️ + +--- + +## Určete číslo $b\in\mathbb{R}$ za předpokladu, že: + +--- +graf funkce $f:y=6x+b$, prochází bodem $A[0;4]$ +$f(0) = 4$ +$6*0 + b = 4$ +$b = 4$ + +--- +graf funkce $f:y=\frac32x+b$, prochází bodem $A[-2;9]$ +$f(-2) = 9$ +$\frac32*(-2)+b=9$ +$-3+b=9$ +$b=12$ + +--- + +## Určete číslo $a\in\mathbb{R}$ za předpokladu, že: + +--- +graf funkce $f:y=ax+2$, prochází bodem $A[-2;6]$ +$f(-2) = 6$ +$-2a+2=6$ +$-2a=4$ +$-a=2$ +$a=-2$ + +--- +graf funkce $f:y=ax-2$, prochází bodem $A[1;2]$ +$f(1)=2$ +$1a-2=2$ +$a=4$ + + +--- +$$ +-5-2x=4x+7 +$$ +$$ +x=-2 +$$ +--- +$$ +8000+100x=10000+80x +$$ +$$ +x=100 +$$ + + +--- +$$x + \frac2x - 1 = \frac{x + 6}{x + 2}$$ +$$x(x+2) + 4 - (x+2) = x + 6 \space | *(x+2)$$ +$[x\neq-2]$ +$$x^2+2x+4-x-2=x+6$$ +$$x^2+x+2=x+6$$ +$$x^2+x-4=x$$ +$$x^2-4=0$$ +$$2 = x$$ + + +--- + +$$\frac{x+2}{x-1}=\frac{x+6}{x+2} \space | *(x-1)(x+2)$$ +$[x\neq1]; [x\neq-2]$ +$$(x+2)^2 = (x+6)(x-1)$$ +$$x^2+4x+4=x^2+5x-6$$ +$$4x+4=5x-6$$ +$$x=10$$ + +--- + +$$\frac{2x+1}{x-3}=\frac{4x+2}{2x-1} \space | *(x-3)(2x-1)$$ +$[x\neq3]; [x\neq\frac12]$ +$$(2x+1)(2x-1)=(4x+2)(x-3)$$ +$$4x^2-1=4x^2-10x-6 \space|-4x^2$$ +$$-1=10x-6 \space |+6$$ +$$5=10x\space|:10$$ +$$x=0.5$$ +$$K=\{-\frac12\}$$ + +--- + +$$\frac{x+3}{x-2}=4+\frac5{x-2} \space | *(x-2)$$ +$[x\neq2]$ +$$x+3=4(x-2)+5$$ +$$x+3=4x-3 \space |-x$$ +$$3=3x-3 \space |+3$$ +$$6=3x \space | :3$$ +$$x=2$$ +$$K=\{\emptyset\}$$ +```ad-sentence +Výsledné x nemá řešení, protože podmínka zakáže výslednou hodnotu (x nesmí být 2, ale x vyšlo 2) +``` + +--- + +$$\frac{x+4}{x+5}=2-\frac1{x+5} \space | *(x+5)$$ +$[x\neq-5]$ +$$x+4=2(x+5)-1$$ +$$x+4=2x+9 \space | -x$$ +$$4=x+9 \space | -9$$ +$$x=-5$$ +$$K=\{\emptyset\}$$ + +--- + +$$\frac{x-2}{x+3}=2-\frac5{x+3} \space | * (x+3)$$ +$[x\neq-3]$ +$$x-2=2(x+3)-5$$ +$$x-2=2x+1 | -x-1$$ +$$x=-3$$ +$$K=\{\emptyset\}$$ +--- + +$$\frac{x+8}{x+3}=1+\frac5{x+3} \space | *(x+3)$$ +$[x\neq-3]$ +$$x+8=1(x+3)+5$$ +$$x+8=x+8 \space | -8$$ +$$0x=0$$ +$$K=\{\mathbb{R} - \{-3\}\}$$ + +--- + +$$\frac{x+2}{x+5} = 1-\frac3{x+5} \space | * (x+5)$$ +$[x\neq-5]$ +$$x+2=x+2 \space | -2-x$$ +$$0x=0$$ +$$K=\{\mathbb{R}-\{-5\}\}$$ + +--- + +$$\frac{x-3}{x+2}=1-\frac6{x+2} \space | *(x+2)$$ +$[x\neq-2]$ +$$x-3=x-4 \space | -x+4$$ +$$1=0x$$ +$$K=\{\emptyset\}$$ + +--- + +$$\frac{2x-4}{x-2}=1-\frac2{x-2} \space | *(x-2)$$ +$[x\neq2]$ +$$2x-4=x-4 | +4$$ +$$2x=x \space |-x$$ +$$x=0$$ +$$K={0}$$ + +--- + +$$\frac{x+3}5 = x$$ +$$\frac{x+3}5-x=0$$ +$$x+3-5x=0$$ +$$-4x+3=0$$ +$$4x=3$$ +$$x=\frac34$$ +--- +$$7(1-x)-4(x-8)=(2-x)11$$ +$$7-7x-4x+32=22-11x$$ +$$-11x+39=22-11x$$ +$$39\neq22$$ + +--- + +$$\frac{3+2x}2-\frac76=5x-\frac{12x-1}3$$ +$$9+6x-7=30x-24x+2$$ +$$6x+2=6x+2$$ +$$2=2$$ +--- + +$$x-6=\frac{7x-3}3-\frac{3(x+2)}4$$ +$$12x-72=28x-12-9x-18$$ +$$12x-72=27x-30$$ +$$-72=7x-30$$ +$$-42=4x$$ +$$x=-6$$ +--- +$$a(a-1)+3=(a+2)(a-2)$$ +$$aa-a+3=aa-4$$ +$$-a+3=-4$$ +$$a=7$$ +--- +$$x-(3x-(4x-(3x-1)-1)+3)=-5$$ +$$x-3x-3+4x-1-3x+1=-5$$ +$$-x-3=-5$$ +$$x=2$$ +--- +$$x-3(x-5(x-4))=10(x-3)$$ +$$x-3x+15x-60=10x-30$$ +$$13x-60=10x-30$$ +$$3x-60=-30$$ +$$x=10$$ +--- +$$3-\frac32(\frac{5x}6-2)=(1\frac12)x-\frac12(\frac12x-9.5)$$ +$$3-\frac{15*6x}{2}+\frac62=1.5x-\frac{x}4+\frac{9.5}2$$ +$$12-30*6x+12=6x-x+19$$ +$$\frac1{37}=x$$ +🤷 + +--- +$$\frac6{x-5}+1=\frac{2x-4}{x-5}$$ +$$6+x-5=2x-4$$ +$$x=5$$ +nemůže být + +--- +$$\frac{2x+5}{x+2}+\frac1{2+x}=3$$ +$$2x+5+1=3x+6$$ +$$2x+6=3x+6$$ +$$x=0$$ +--- +$$\frac{2x+4}{3x-1}=\frac25-\frac{x+5}{1-3x}$$ +$$\frac{2x+4}{3x-1}=\frac25+\frac{x+5}{3x-1}$$ +$$2x+4=\frac{2(3x-1)}5 +x+5$$ +$$x=\frac{6x-2}5+1$$ +$$x=-3$$ +--- +$$\frac{x+7}{x-5}+\frac{x+5}{x-7}=2$$ +$$(x+7)(x-7)+(x+5)(x-5)=2(x-5)(x-7)$$ +$$x^2-7^2+x^2-5^2=2(x^2-7x-5x+35)$$ +$$2x^2-7^2-5^2=2x^2-14x-10x+70$$ +$$2x^2-49-25=2x^2-24x+70$$ +$$2x^2-74=2x^2-24x+70$$ + +$$24x=144$$ +$$x=6$$ +--- +$$\frac{17}{x+1}-\frac5{x^2+x}=\frac6x$$ +$$\frac{17}{x+1}-\frac5{x(x+1)}=\frac6x \space | :x(x+1)$$ +$$17x-5=6(x+1)$$ +$$17x-5=6x+6 |+5$$ +$$11x=11$$ +$$x=1$$