Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(x^2-196=0\)
- \(3(10x^2+10)=-(-33x^2+402)\)
- \(5x^2+320=0\)
- \(8x^2+1800=0\)
- \(-4(9x^2-9)=-(29x^2+1336)\)
- \(-4x^2+324=0\)
- \(7x^2+0=0\)
- \(-3x^2-432=0\)
- \(5x^2-297=2x^2+3\)
- \(4(-10x^2-10)=-(48x^2-160)\)
- \(x^2-121=0\)
- \(4(-4x^2-7)=-(21x^2+28)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(x^2-196=0 \\
\Leftrightarrow x^2 = 196 \\
\Leftrightarrow x^2 = \frac{196}{1}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(3(10x^2+10)=-(-33x^2+402) \\ \Leftrightarrow 30x^2+30=33x^2-402 \\
\Leftrightarrow 30x^2-33x^2=-402-30 \\
\Leftrightarrow -3x^2 = -432 \\
\Leftrightarrow x^2 = \frac{-432}{-3}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(5x^2+320=0 \\
\Leftrightarrow 5x^2 = -320 \\
\Leftrightarrow x^2 = \frac{-320}{5} < 0 \\
V = \varnothing \\ -----------------\)
- \(8x^2+1800=0 \\
\Leftrightarrow 8x^2 = -1800 \\
\Leftrightarrow x^2 = \frac{-1800}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(-4(9x^2-9)=-(29x^2+1336) \\ \Leftrightarrow -36x^2+36=-29x^2-1336 \\
\Leftrightarrow -36x^2+29x^2=-1336-36 \\
\Leftrightarrow -7x^2 = -1372 \\
\Leftrightarrow x^2 = \frac{-1372}{-7}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(-4x^2+324=0 \\
\Leftrightarrow -4x^2 = -324 \\
\Leftrightarrow x^2 = \frac{-324}{-4}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)
- \(7x^2+0=0 \\
\Leftrightarrow 7x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{7}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-3x^2-432=0 \\
\Leftrightarrow -3x^2 = 432 \\
\Leftrightarrow x^2 = \frac{432}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(5x^2-297=2x^2+3 \\ \Leftrightarrow 5x^2-2x^2=3+297 \\
\Leftrightarrow 3x^2 = 300 \\
\Leftrightarrow x^2 = \frac{300}{3}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(4(-10x^2-10)=-(48x^2-160) \\ \Leftrightarrow -40x^2-40=-48x^2+160 \\
\Leftrightarrow -40x^2+48x^2=160+40 \\
\Leftrightarrow 8x^2 = 200 \\
\Leftrightarrow x^2 = \frac{200}{8}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(x^2-121=0 \\
\Leftrightarrow x^2 = 121 \\
\Leftrightarrow x^2 = \frac{121}{1}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(4(-4x^2-7)=-(21x^2+28) \\ \Leftrightarrow -16x^2-28=-21x^2-28 \\
\Leftrightarrow -16x^2+21x^2=-28+28 \\
\Leftrightarrow 5x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{5}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)