Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(7x^2+202=6x^2+6\)
- \(3x^2-12=0\)
- \(-11x^2+594=-8x^2+6\)
- \(2(-2x^2+6)=-(x^2+231)\)
- \(5x^2+605=0\)
- \(-7x^2+1372=0\)
- \(-2x^2-4=-8x^2-4\)
- \(2(-8x^2+6)=-(18x^2+6)\)
- \(4(9x^2-9)=-(-38x^2-206)\)
- \(5x^2-500=0\)
- \(2x^2-98=0\)
- \(-3x^2+192=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(7x^2+202=6x^2+6 \\ \Leftrightarrow 7x^2-6x^2=6-202 \\
\Leftrightarrow x^2 = -196 \\
\Leftrightarrow x^2 = \frac{-196}{1} < 0 \\
V = \varnothing \\ -----------------\)
- \(3x^2-12=0 \\
\Leftrightarrow 3x^2 = 12 \\
\Leftrightarrow x^2 = \frac{12}{3}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(-11x^2+594=-8x^2+6 \\ \Leftrightarrow -11x^2+8x^2=6-594 \\
\Leftrightarrow -3x^2 = -588 \\
\Leftrightarrow x^2 = \frac{-588}{-3}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(2(-2x^2+6)=-(x^2+231) \\ \Leftrightarrow -4x^2+12=-x^2-231 \\
\Leftrightarrow -4x^2+x^2=-231-12 \\
\Leftrightarrow -3x^2 = -243 \\
\Leftrightarrow x^2 = \frac{-243}{-3}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)
- \(5x^2+605=0 \\
\Leftrightarrow 5x^2 = -605 \\
\Leftrightarrow x^2 = \frac{-605}{5} < 0 \\
V = \varnothing \\ -----------------\)
- \(-7x^2+1372=0 \\
\Leftrightarrow -7x^2 = -1372 \\
\Leftrightarrow x^2 = \frac{-1372}{-7}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(-2x^2-4=-8x^2-4 \\ \Leftrightarrow -2x^2+8x^2=-4+4 \\
\Leftrightarrow 6x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{6}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(2(-8x^2+6)=-(18x^2+6) \\ \Leftrightarrow -16x^2+12=-18x^2-6 \\
\Leftrightarrow -16x^2+18x^2=-6-12 \\
\Leftrightarrow 2x^2 = -18 \\
\Leftrightarrow x^2 = \frac{-18}{2} < 0 \\
V = \varnothing \\ -----------------\)
- \(4(9x^2-9)=-(-38x^2-206) \\ \Leftrightarrow 36x^2-36=38x^2+206 \\
\Leftrightarrow 36x^2-38x^2=206+36 \\
\Leftrightarrow -2x^2 = 242 \\
\Leftrightarrow x^2 = \frac{242}{-2} < 0 \\
V = \varnothing \\ -----------------\)
- \(5x^2-500=0 \\
\Leftrightarrow 5x^2 = 500 \\
\Leftrightarrow x^2 = \frac{500}{5}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(2x^2-98=0 \\
\Leftrightarrow 2x^2 = 98 \\
\Leftrightarrow x^2 = \frac{98}{2}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(-3x^2+192=0 \\
\Leftrightarrow -3x^2 = -192 \\
\Leftrightarrow x^2 = \frac{-192}{-3}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)