Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-4x^2+1347=4x^2-5\)
- \(3(3x^2-5)=-(-2x^2-13)\)
- \(4(-10x^2+5)=-(33x^2+92)\)
- \(-4(-9x^2+5)=-(-31x^2-825)\)
- \(8x^2+1568=0\)
- \(5x^2-500=0\)
- \(3x^2-3=6x^2-3\)
- \(-4x^2+0=0\)
- \(x^2+333=-6x^2-10\)
- \(4(-4x^2+6)=-(18x^2-74)\)
- \(4(8x^2-9)=-(-31x^2+205)\)
- \(-x^2+144=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-4x^2+1347=4x^2-5 \\ \Leftrightarrow -4x^2-4x^2=-5-1347 \\
\Leftrightarrow -8x^2 = -1352 \\
\Leftrightarrow x^2 = \frac{-1352}{-8}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(3(3x^2-5)=-(-2x^2-13) \\ \Leftrightarrow 9x^2-15=2x^2+13 \\
\Leftrightarrow 9x^2-2x^2=13+15 \\
\Leftrightarrow 7x^2 = 28 \\
\Leftrightarrow x^2 = \frac{28}{7}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(4(-10x^2+5)=-(33x^2+92) \\ \Leftrightarrow -40x^2+20=-33x^2-92 \\
\Leftrightarrow -40x^2+33x^2=-92-20 \\
\Leftrightarrow -7x^2 = -112 \\
\Leftrightarrow x^2 = \frac{-112}{-7}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(-4(-9x^2+5)=-(-31x^2-825) \\ \Leftrightarrow 36x^2-20=31x^2+825 \\
\Leftrightarrow 36x^2-31x^2=825+20 \\
\Leftrightarrow 5x^2 = 845 \\
\Leftrightarrow x^2 = \frac{845}{5}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(8x^2+1568=0 \\
\Leftrightarrow 8x^2 = -1568 \\
\Leftrightarrow x^2 = \frac{-1568}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(5x^2-500=0 \\
\Leftrightarrow 5x^2 = 500 \\
\Leftrightarrow x^2 = \frac{500}{5}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(3x^2-3=6x^2-3 \\ \Leftrightarrow 3x^2-6x^2=-3+3 \\
\Leftrightarrow -3x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-3}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-4x^2+0=0 \\
\Leftrightarrow -4x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-4}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(x^2+333=-6x^2-10 \\ \Leftrightarrow x^2+6x^2=-10-333 \\
\Leftrightarrow 7x^2 = -343 \\
\Leftrightarrow x^2 = \frac{-343}{7} < 0 \\
V = \varnothing \\ -----------------\)
- \(4(-4x^2+6)=-(18x^2-74) \\ \Leftrightarrow -16x^2+24=-18x^2+74 \\
\Leftrightarrow -16x^2+18x^2=74-24 \\
\Leftrightarrow 2x^2 = 50 \\
\Leftrightarrow x^2 = \frac{50}{2}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(4(8x^2-9)=-(-31x^2+205) \\ \Leftrightarrow 32x^2-36=31x^2-205 \\
\Leftrightarrow 32x^2-31x^2=-205+36 \\
\Leftrightarrow x^2 = -169 \\
\Leftrightarrow x^2 = \frac{-169}{1} < 0 \\
V = \varnothing \\ -----------------\)
- \(-x^2+144=0 \\
\Leftrightarrow -x^2 = -144 \\
\Leftrightarrow x^2 = \frac{-144}{-1}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)