Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-2x^2+8=0\)
- \(6x^2+96=0\)
- \(-3x^2+432=0\)
- \(-4x^2+4=0\)
- \(-2x^2-392=0\)
- \(16x^2-52=10x^2+2\)
- \(-9x^2+1022=-3x^2+8\)
- \(-3(8x^2-8)=-(27x^2-51)\)
- \(9x^2-5=6x^2-5\)
- \(6x^2+150=0\)
- \(-15x^2+1185=-9x^2+9\)
- \(7x^2-1372=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-2x^2+8=0 \\
\Leftrightarrow -2x^2 = -8 \\
\Leftrightarrow x^2 = \frac{-8}{-2}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(6x^2+96=0 \\
\Leftrightarrow 6x^2 = -96 \\
\Leftrightarrow x^2 = \frac{-96}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3x^2+432=0 \\
\Leftrightarrow -3x^2 = -432 \\
\Leftrightarrow x^2 = \frac{-432}{-3}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(-4x^2+4=0 \\
\Leftrightarrow -4x^2 = -4 \\
\Leftrightarrow x^2 = \frac{-4}{-4}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(-2x^2-392=0 \\
\Leftrightarrow -2x^2 = 392 \\
\Leftrightarrow x^2 = \frac{392}{-2} < 0 \\
V = \varnothing \\ -----------------\)
- \(16x^2-52=10x^2+2 \\ \Leftrightarrow 16x^2-10x^2=2+52 \\
\Leftrightarrow 6x^2 = 54 \\
\Leftrightarrow x^2 = \frac{54}{6}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(-9x^2+1022=-3x^2+8 \\ \Leftrightarrow -9x^2+3x^2=8-1022 \\
\Leftrightarrow -6x^2 = -1014 \\
\Leftrightarrow x^2 = \frac{-1014}{-6}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-3(8x^2-8)=-(27x^2-51) \\ \Leftrightarrow -24x^2+24=-27x^2+51 \\
\Leftrightarrow -24x^2+27x^2=51-24 \\
\Leftrightarrow 3x^2 = 27 \\
\Leftrightarrow x^2 = \frac{27}{3}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(9x^2-5=6x^2-5 \\ \Leftrightarrow 9x^2-6x^2=-5+5 \\
\Leftrightarrow 3x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{3}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(6x^2+150=0 \\
\Leftrightarrow 6x^2 = -150 \\
\Leftrightarrow x^2 = \frac{-150}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(-15x^2+1185=-9x^2+9 \\ \Leftrightarrow -15x^2+9x^2=9-1185 \\
\Leftrightarrow -6x^2 = -1176 \\
\Leftrightarrow x^2 = \frac{-1176}{-6}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(7x^2-1372=0 \\
\Leftrightarrow 7x^2 = 1372 \\
\Leftrightarrow x^2 = \frac{1372}{7}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)