Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(x^2-49=0\)
- \(8x^2+1152=0\)
- \(15x^2-1567=8x^2+8\)
- \(4(-8x^2-7)=-(34x^2+30)\)
- \(-17x^2-2=-10x^2-9\)
- \(4(4x^2-9)=-(-11x^2+881)\)
- \(-4(4x^2+4)=-(24x^2-952)\)
- \(-3(-4x^2+2)=-(-9x^2+438)\)
- \(2(8x^2+2)=-(-12x^2+12)\)
- \(-4(9x^2+3)=-(29x^2+460)\)
- \(4(-7x^2-10)=-(33x^2+40)\)
- \(4x^2-400=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(x^2-49=0 \\
\Leftrightarrow x^2 = 49 \\
\Leftrightarrow x^2 = \frac{49}{1}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(8x^2+1152=0 \\
\Leftrightarrow 8x^2 = -1152 \\
\Leftrightarrow x^2 = \frac{-1152}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(15x^2-1567=8x^2+8 \\ \Leftrightarrow 15x^2-8x^2=8+1567 \\
\Leftrightarrow 7x^2 = 1575 \\
\Leftrightarrow x^2 = \frac{1575}{7}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(4(-8x^2-7)=-(34x^2+30) \\ \Leftrightarrow -32x^2-28=-34x^2-30 \\
\Leftrightarrow -32x^2+34x^2=-30+28 \\
\Leftrightarrow 2x^2 = -2 \\
\Leftrightarrow x^2 = \frac{-2}{2} < 0 \\
V = \varnothing \\ -----------------\)
- \(-17x^2-2=-10x^2-9 \\ \Leftrightarrow -17x^2+10x^2=-9+2 \\
\Leftrightarrow -7x^2 = -7 \\
\Leftrightarrow x^2 = \frac{-7}{-7}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(4(4x^2-9)=-(-11x^2+881) \\ \Leftrightarrow 16x^2-36=11x^2-881 \\
\Leftrightarrow 16x^2-11x^2=-881+36 \\
\Leftrightarrow 5x^2 = -845 \\
\Leftrightarrow x^2 = \frac{-845}{5} < 0 \\
V = \varnothing \\ -----------------\)
- \(-4(4x^2+4)=-(24x^2-952) \\ \Leftrightarrow -16x^2-16=-24x^2+952 \\
\Leftrightarrow -16x^2+24x^2=952+16 \\
\Leftrightarrow 8x^2 = 968 \\
\Leftrightarrow x^2 = \frac{968}{8}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(-3(-4x^2+2)=-(-9x^2+438) \\ \Leftrightarrow 12x^2-6=9x^2-438 \\
\Leftrightarrow 12x^2-9x^2=-438+6 \\
\Leftrightarrow 3x^2 = -432 \\
\Leftrightarrow x^2 = \frac{-432}{3} < 0 \\
V = \varnothing \\ -----------------\)
- \(2(8x^2+2)=-(-12x^2+12) \\ \Leftrightarrow 16x^2+4=12x^2-12 \\
\Leftrightarrow 16x^2-12x^2=-12-4 \\
\Leftrightarrow 4x^2 = -16 \\
\Leftrightarrow x^2 = \frac{-16}{4} < 0 \\
V = \varnothing \\ -----------------\)
- \(-4(9x^2+3)=-(29x^2+460) \\ \Leftrightarrow -36x^2-12=-29x^2-460 \\
\Leftrightarrow -36x^2+29x^2=-460+12 \\
\Leftrightarrow -7x^2 = -448 \\
\Leftrightarrow x^2 = \frac{-448}{-7}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(4(-7x^2-10)=-(33x^2+40) \\ \Leftrightarrow -28x^2-40=-33x^2-40 \\
\Leftrightarrow -28x^2+33x^2=-40+40 \\
\Leftrightarrow 5x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{5}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(4x^2-400=0 \\
\Leftrightarrow 4x^2 = 400 \\
\Leftrightarrow x^2 = \frac{400}{4}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)