Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(11x^2-208=5x^2+8\)
- \(-3(-4x^2+10)=-(-4x^2-258)\)
- \(15x^2-10=9x^2-4\)
- \(-8x^2-1800=0\)
- \(2(-3x^2+2)=-(2x^2+0)\)
- \(2x^2+288=0\)
- \(-3x^2+48=0\)
- \(8x^2-800=0\)
- \(-6x^2-9=-10x^2-9\)
- \(-5x^2+0=0\)
- \(4x^2+256=0\)
- \(2(-8x^2+5)=-(20x^2-910)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(11x^2-208=5x^2+8 \\ \Leftrightarrow 11x^2-5x^2=8+208 \\
\Leftrightarrow 6x^2 = 216 \\
\Leftrightarrow x^2 = \frac{216}{6}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(-3(-4x^2+10)=-(-4x^2-258) \\ \Leftrightarrow 12x^2-30=4x^2+258 \\
\Leftrightarrow 12x^2-4x^2=258+30 \\
\Leftrightarrow 8x^2 = 288 \\
\Leftrightarrow x^2 = \frac{288}{8}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(15x^2-10=9x^2-4 \\ \Leftrightarrow 15x^2-9x^2=-4+10 \\
\Leftrightarrow 6x^2 = 6 \\
\Leftrightarrow x^2 = \frac{6}{6}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(-8x^2-1800=0 \\
\Leftrightarrow -8x^2 = 1800 \\
\Leftrightarrow x^2 = \frac{1800}{-8} < 0 \\
V = \varnothing \\ -----------------\)
- \(2(-3x^2+2)=-(2x^2+0) \\ \Leftrightarrow -6x^2+4=-2x^2+0 \\
\Leftrightarrow -6x^2+2x^2=0-4 \\
\Leftrightarrow -4x^2 = -4 \\
\Leftrightarrow x^2 = \frac{-4}{-4}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(2x^2+288=0 \\
\Leftrightarrow 2x^2 = -288 \\
\Leftrightarrow x^2 = \frac{-288}{2} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3x^2+48=0 \\
\Leftrightarrow -3x^2 = -48 \\
\Leftrightarrow x^2 = \frac{-48}{-3}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(8x^2-800=0 \\
\Leftrightarrow 8x^2 = 800 \\
\Leftrightarrow x^2 = \frac{800}{8}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(-6x^2-9=-10x^2-9 \\ \Leftrightarrow -6x^2+10x^2=-9+9 \\
\Leftrightarrow 4x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{4}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-5x^2+0=0 \\
\Leftrightarrow -5x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-5}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(4x^2+256=0 \\
\Leftrightarrow 4x^2 = -256 \\
\Leftrightarrow x^2 = \frac{-256}{4} < 0 \\
V = \varnothing \\ -----------------\)
- \(2(-8x^2+5)=-(20x^2-910) \\ \Leftrightarrow -16x^2+10=-20x^2+910 \\
\Leftrightarrow -16x^2+20x^2=910-10 \\
\Leftrightarrow 4x^2 = 900 \\
\Leftrightarrow x^2 = \frac{900}{4}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)