Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(5(-2x^2-8)=-(16x^2+424)\)
- \(2(-7x^2-2)=-(20x^2-20)\)
- \(8x^2-968=0\)
- \(x^2-169=0\)
- \(-2x^2+392=0\)
- \(-x^2+239=-6x^2-6\)
- \(-2(3x^2-4)=-(14x^2+64)\)
- \(4(-3x^2-6)=-(7x^2+869)\)
- \(-4(-6x^2+2)=-(-28x^2+4)\)
- \(-8x^2+968=0\)
- \(-4x^2+0=0\)
- \(5x^2+516=-3x^2+4\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(5(-2x^2-8)=-(16x^2+424) \\ \Leftrightarrow -10x^2-40=-16x^2-424 \\
\Leftrightarrow -10x^2+16x^2=-424+40 \\
\Leftrightarrow 6x^2 = -384 \\
\Leftrightarrow x^2 = \frac{-384}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(2(-7x^2-2)=-(20x^2-20) \\ \Leftrightarrow -14x^2-4=-20x^2+20 \\
\Leftrightarrow -14x^2+20x^2=20+4 \\
\Leftrightarrow 6x^2 = 24 \\
\Leftrightarrow x^2 = \frac{24}{6}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(8x^2-968=0 \\
\Leftrightarrow 8x^2 = 968 \\
\Leftrightarrow x^2 = \frac{968}{8}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(x^2-169=0 \\
\Leftrightarrow x^2 = 169 \\
\Leftrightarrow x^2 = \frac{169}{1}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-2x^2+392=0 \\
\Leftrightarrow -2x^2 = -392 \\
\Leftrightarrow x^2 = \frac{-392}{-2}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(-x^2+239=-6x^2-6 \\ \Leftrightarrow -x^2+6x^2=-6-239 \\
\Leftrightarrow 5x^2 = -245 \\
\Leftrightarrow x^2 = \frac{-245}{5} < 0 \\
V = \varnothing \\ -----------------\)
- \(-2(3x^2-4)=-(14x^2+64) \\ \Leftrightarrow -6x^2+8=-14x^2-64 \\
\Leftrightarrow -6x^2+14x^2=-64-8 \\
\Leftrightarrow 8x^2 = -72 \\
\Leftrightarrow x^2 = \frac{-72}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(4(-3x^2-6)=-(7x^2+869) \\ \Leftrightarrow -12x^2-24=-7x^2-869 \\
\Leftrightarrow -12x^2+7x^2=-869+24 \\
\Leftrightarrow -5x^2 = -845 \\
\Leftrightarrow x^2 = \frac{-845}{-5}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-4(-6x^2+2)=-(-28x^2+4) \\ \Leftrightarrow 24x^2-8=28x^2-4 \\
\Leftrightarrow 24x^2-28x^2=-4+8 \\
\Leftrightarrow -4x^2 = 4 \\
\Leftrightarrow x^2 = \frac{4}{-4} < 0 \\
V = \varnothing \\ -----------------\)
- \(-8x^2+968=0 \\
\Leftrightarrow -8x^2 = -968 \\
\Leftrightarrow x^2 = \frac{-968}{-8}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(-4x^2+0=0 \\
\Leftrightarrow -4x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-4}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(5x^2+516=-3x^2+4 \\ \Leftrightarrow 5x^2+3x^2=4-516 \\
\Leftrightarrow 8x^2 = -512 \\
\Leftrightarrow x^2 = \frac{-512}{8} < 0 \\
V = \varnothing \\ -----------------\)