Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-4x^2+196=0\)
- \(4x^2-4=0\)
- \(7x^2-66=4x^2+9\)
- \(-5(3x^2-5)=-(17x^2-225)\)
- \(-x^2-5=-3x^2+3\)
- \(x^2+10=3x^2+10\)
- \(4(-6x^2+4)=-(29x^2+229)\)
- \(5x^2+192=-3x^2-8\)
- \(12x^2-597=7x^2+8\)
- \(3x^2-432=0\)
- \(4(9x^2+10)=-(-43x^2+23)\)
- \(-4(4x^2-2)=-(15x^2-8)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-4x^2+196=0 \\
\Leftrightarrow -4x^2 = -196 \\
\Leftrightarrow x^2 = \frac{-196}{-4}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(4x^2-4=0 \\
\Leftrightarrow 4x^2 = 4 \\
\Leftrightarrow x^2 = \frac{4}{4}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(7x^2-66=4x^2+9 \\ \Leftrightarrow 7x^2-4x^2=9+66 \\
\Leftrightarrow 3x^2 = 75 \\
\Leftrightarrow x^2 = \frac{75}{3}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(-5(3x^2-5)=-(17x^2-225) \\ \Leftrightarrow -15x^2+25=-17x^2+225 \\
\Leftrightarrow -15x^2+17x^2=225-25 \\
\Leftrightarrow 2x^2 = 200 \\
\Leftrightarrow x^2 = \frac{200}{2}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(-x^2-5=-3x^2+3 \\ \Leftrightarrow -x^2+3x^2=3+5 \\
\Leftrightarrow 2x^2 = 8 \\
\Leftrightarrow x^2 = \frac{8}{2}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(x^2+10=3x^2+10 \\ \Leftrightarrow x^2-3x^2=10-10 \\
\Leftrightarrow -2x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-2}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(4(-6x^2+4)=-(29x^2+229) \\ \Leftrightarrow -24x^2+16=-29x^2-229 \\
\Leftrightarrow -24x^2+29x^2=-229-16 \\
\Leftrightarrow 5x^2 = -245 \\
\Leftrightarrow x^2 = \frac{-245}{5} < 0 \\
V = \varnothing \\ -----------------\)
- \(5x^2+192=-3x^2-8 \\ \Leftrightarrow 5x^2+3x^2=-8-192 \\
\Leftrightarrow 8x^2 = -200 \\
\Leftrightarrow x^2 = \frac{-200}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(12x^2-597=7x^2+8 \\ \Leftrightarrow 12x^2-7x^2=8+597 \\
\Leftrightarrow 5x^2 = 605 \\
\Leftrightarrow x^2 = \frac{605}{5}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(3x^2-432=0 \\
\Leftrightarrow 3x^2 = 432 \\
\Leftrightarrow x^2 = \frac{432}{3}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(4(9x^2+10)=-(-43x^2+23) \\ \Leftrightarrow 36x^2+40=43x^2-23 \\
\Leftrightarrow 36x^2-43x^2=-23-40 \\
\Leftrightarrow -7x^2 = -63 \\
\Leftrightarrow x^2 = \frac{-63}{-7}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(-4(4x^2-2)=-(15x^2-8) \\ \Leftrightarrow -16x^2+8=-15x^2+8 \\
\Leftrightarrow -16x^2+15x^2=8-8 \\
\Leftrightarrow -x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-1}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)