Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(2(-7x^2+9)=-(17x^2-18)\)
- \(-2x^2+1340=-8x^2-10\)
- \(x^2+169=0\)
- \(3(-6x^2+8)=-(21x^2+24)\)
- \(4x^2+4=0\)
- \(11x^2-5=9x^2-5\)
- \(8x^2-968=0\)
- \(15x^2-1018=9x^2-4\)
- \(13x^2-57=9x^2+7\)
- \(6x^2+864=0\)
- \(-x^2-669=-5x^2+7\)
- \(-6x^2+384=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(2(-7x^2+9)=-(17x^2-18) \\ \Leftrightarrow -14x^2+18=-17x^2+18 \\
\Leftrightarrow -14x^2+17x^2=18-18 \\
\Leftrightarrow 3x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{3}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-2x^2+1340=-8x^2-10 \\ \Leftrightarrow -2x^2+8x^2=-10-1340 \\
\Leftrightarrow 6x^2 = -1350 \\
\Leftrightarrow x^2 = \frac{-1350}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(x^2+169=0 \\
\Leftrightarrow x^2 = -169 \\
\Leftrightarrow x^2 = \frac{-169}{1} < 0 \\
V = \varnothing \\ -----------------\)
- \(3(-6x^2+8)=-(21x^2+24) \\ \Leftrightarrow -18x^2+24=-21x^2-24 \\
\Leftrightarrow -18x^2+21x^2=-24-24 \\
\Leftrightarrow 3x^2 = -48 \\
\Leftrightarrow x^2 = \frac{-48}{3} < 0 \\
V = \varnothing \\ -----------------\)
- \(4x^2+4=0 \\
\Leftrightarrow 4x^2 = -4 \\
\Leftrightarrow x^2 = \frac{-4}{4} < 0 \\
V = \varnothing \\ -----------------\)
- \(11x^2-5=9x^2-5 \\ \Leftrightarrow 11x^2-9x^2=-5+5 \\
\Leftrightarrow 2x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{2}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(8x^2-968=0 \\
\Leftrightarrow 8x^2 = 968 \\
\Leftrightarrow x^2 = \frac{968}{8}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(15x^2-1018=9x^2-4 \\ \Leftrightarrow 15x^2-9x^2=-4+1018 \\
\Leftrightarrow 6x^2 = 1014 \\
\Leftrightarrow x^2 = \frac{1014}{6}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(13x^2-57=9x^2+7 \\ \Leftrightarrow 13x^2-9x^2=7+57 \\
\Leftrightarrow 4x^2 = 64 \\
\Leftrightarrow x^2 = \frac{64}{4}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(6x^2+864=0 \\
\Leftrightarrow 6x^2 = -864 \\
\Leftrightarrow x^2 = \frac{-864}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(-x^2-669=-5x^2+7 \\ \Leftrightarrow -x^2+5x^2=7+669 \\
\Leftrightarrow 4x^2 = 676 \\
\Leftrightarrow x^2 = \frac{676}{4}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-6x^2+384=0 \\
\Leftrightarrow -6x^2 = -384 \\
\Leftrightarrow x^2 = \frac{-384}{-6}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)