Zadanie 10
a)
f(x)=\frac{2}{x^2} , x\ne0 , x \in R-{0}
A(a,8)
8=\frac{2}{a^2} , a\ne 0
a^2=\frac{2}{8}
a^2=\frac{1}{4}
a=-\frac{1}{2} lub a=\frac{1}{2}
B(1,b)
b=\frac{2}{1^2}=2
C(\sqrt2,c)
c=\frac{2}{(\sqrt2)^2}=\frac{2}{2}=1
D(3\sqrt2,d)
d=\frac{2}{(3\sqrt2)^2}=\frac{2}{9*2}=\frac{1}{9}
b)
f(x)=\frac{1}{\sqrt {x}} , x>0 D_f=(0;+\infty)
A(a,2)
2=\frac{1}{\sqrt a} , a>0
\sqrt{a}=\frac{1}{2}
2\sqrt {a}=1 :2
\sqrt{a}=\frac{1}{2} |()^2
a=\frac{1}{4}
B(b,1)
1=\frac{1}{\sqrt{b}} , b>0
\sqrt{b}=1 |()^2
b=1
C(4,c)
c=\frac{1}{\sqrt4}=\frac{1}{2}
D(2,d)
d=\frac{1}{\sqrt{12}}=\frac{1}{\sqrt{4*3}}=\frac{1}{2\sqrt{3}}=\frac{\sqrt3}{2\sqrt3*\sqrt3}=\frac{\sqrt3}{2*3}=\frac{\sqrt3}{6}