Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(9x^2-2=3x^2-2\)
- \(x^2-188=-3x^2+8\)
- \(2x^2-72=0\)
- \(-18x^2+285=-10x^2-3\)
- \(2(5x^2+10)=-(-2x^2-532)\)
- \(8x^2-1800=0\)
- \(4x^2-4=0\)
- \(5x^2+162=6x^2-7\)
- \(-3x^2-110=-4x^2-10\)
- \(3(5x^2+6)=-(-11x^2-694)\)
- \(-3x^2-363=0\)
- \(11x^2+479=7x^2-5\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(9x^2-2=3x^2-2 \\ \Leftrightarrow 9x^2-3x^2=-2+2 \\
\Leftrightarrow 6x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{6}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(x^2-188=-3x^2+8 \\ \Leftrightarrow x^2+3x^2=8+188 \\
\Leftrightarrow 4x^2 = 196 \\
\Leftrightarrow x^2 = \frac{196}{4}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(2x^2-72=0 \\
\Leftrightarrow 2x^2 = 72 \\
\Leftrightarrow x^2 = \frac{72}{2}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(-18x^2+285=-10x^2-3 \\ \Leftrightarrow -18x^2+10x^2=-3-285 \\
\Leftrightarrow -8x^2 = -288 \\
\Leftrightarrow x^2 = \frac{-288}{-8}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(2(5x^2+10)=-(-2x^2-532) \\ \Leftrightarrow 10x^2+20=2x^2+532 \\
\Leftrightarrow 10x^2-2x^2=532-20 \\
\Leftrightarrow 8x^2 = 512 \\
\Leftrightarrow x^2 = \frac{512}{8}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(8x^2-1800=0 \\
\Leftrightarrow 8x^2 = 1800 \\
\Leftrightarrow x^2 = \frac{1800}{8}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(4x^2-4=0 \\
\Leftrightarrow 4x^2 = 4 \\
\Leftrightarrow x^2 = \frac{4}{4}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(5x^2+162=6x^2-7 \\ \Leftrightarrow 5x^2-6x^2=-7-162 \\
\Leftrightarrow -x^2 = -169 \\
\Leftrightarrow x^2 = \frac{-169}{-1}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-3x^2-110=-4x^2-10 \\ \Leftrightarrow -3x^2+4x^2=-10+110 \\
\Leftrightarrow x^2 = 100 \\
\Leftrightarrow x^2 = \frac{100}{1}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(3(5x^2+6)=-(-11x^2-694) \\ \Leftrightarrow 15x^2+18=11x^2+694 \\
\Leftrightarrow 15x^2-11x^2=694-18 \\
\Leftrightarrow 4x^2 = 676 \\
\Leftrightarrow x^2 = \frac{676}{4}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-3x^2-363=0 \\
\Leftrightarrow -3x^2 = 363 \\
\Leftrightarrow x^2 = \frac{363}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(11x^2+479=7x^2-5 \\ \Leftrightarrow 11x^2-7x^2=-5-479 \\
\Leftrightarrow 4x^2 = -484 \\
\Leftrightarrow x^2 = \frac{-484}{4} < 0 \\
V = \varnothing \\ -----------------\)