Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(x^2+0=0\)
- \(4(-9x^2+6)=-(29x^2-472)\)
- \(-3x^2-108=0\)
- \(5x^2+980=0\)
- \(-4x^2+4=0\)
- \(x^2+40=2x^2+4\)
- \(3x^2-51=-2x^2-6\)
- \(-x^2-225=0\)
- \(2x^2+0=0\)
- \(-5(-3x^2-2)=-(-11x^2-686)\)
- \(-5(-4x^2+5)=-(-23x^2+217)\)
- \(-3(-7x^2+5)=-(-20x^2+24)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(x^2+0=0 \\
\Leftrightarrow x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{1}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(4(-9x^2+6)=-(29x^2-472) \\ \Leftrightarrow -36x^2+24=-29x^2+472 \\
\Leftrightarrow -36x^2+29x^2=472-24 \\
\Leftrightarrow -7x^2 = 448 \\
\Leftrightarrow x^2 = \frac{448}{-7} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3x^2-108=0 \\
\Leftrightarrow -3x^2 = 108 \\
\Leftrightarrow x^2 = \frac{108}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(5x^2+980=0 \\
\Leftrightarrow 5x^2 = -980 \\
\Leftrightarrow x^2 = \frac{-980}{5} < 0 \\
V = \varnothing \\ -----------------\)
- \(-4x^2+4=0 \\
\Leftrightarrow -4x^2 = -4 \\
\Leftrightarrow x^2 = \frac{-4}{-4}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(x^2+40=2x^2+4 \\ \Leftrightarrow x^2-2x^2=4-40 \\
\Leftrightarrow -x^2 = -36 \\
\Leftrightarrow x^2 = \frac{-36}{-1}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(3x^2-51=-2x^2-6 \\ \Leftrightarrow 3x^2+2x^2=-6+51 \\
\Leftrightarrow 5x^2 = 45 \\
\Leftrightarrow x^2 = \frac{45}{5}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(-x^2-225=0 \\
\Leftrightarrow -x^2 = 225 \\
\Leftrightarrow x^2 = \frac{225}{-1} < 0 \\
V = \varnothing \\ -----------------\)
- \(2x^2+0=0 \\
\Leftrightarrow 2x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{2}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-5(-3x^2-2)=-(-11x^2-686) \\ \Leftrightarrow 15x^2+10=11x^2+686 \\
\Leftrightarrow 15x^2-11x^2=686-10 \\
\Leftrightarrow 4x^2 = 676 \\
\Leftrightarrow x^2 = \frac{676}{4}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-5(-4x^2+5)=-(-23x^2+217) \\ \Leftrightarrow 20x^2-25=23x^2-217 \\
\Leftrightarrow 20x^2-23x^2=-217+25 \\
\Leftrightarrow -3x^2 = -192 \\
\Leftrightarrow x^2 = \frac{-192}{-3}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(-3(-7x^2+5)=-(-20x^2+24) \\ \Leftrightarrow 21x^2-15=20x^2-24 \\
\Leftrightarrow 21x^2-20x^2=-24+15 \\
\Leftrightarrow x^2 = -9 \\
\Leftrightarrow x^2 = \frac{-9}{1} < 0 \\
V = \varnothing \\ -----------------\)