Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-5(-3x^2+10)=-(-17x^2-22)\)
- \(6x^2-384=0\)
- \(-4(-6x^2+5)=-(-23x^2+20)\)
- \(-13x^2+7=-8x^2+7\)
- \(-3(5x^2-6)=-(8x^2+1557)\)
- \(4(-10x^2-3)=-(34x^2+108)\)
- \(3x^2+300=0\)
- \(-4(9x^2+3)=-(28x^2+12)\)
- \(-3x^2-588=0\)
- \(7x^2-219=8x^2+6\)
- \(-6x^2-6=0\)
- \(-6x^2-14=-8x^2-6\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-5(-3x^2+10)=-(-17x^2-22) \\ \Leftrightarrow 15x^2-50=17x^2+22 \\
\Leftrightarrow 15x^2-17x^2=22+50 \\
\Leftrightarrow -2x^2 = 72 \\
\Leftrightarrow x^2 = \frac{72}{-2} < 0 \\
V = \varnothing \\ -----------------\)
- \(6x^2-384=0 \\
\Leftrightarrow 6x^2 = 384 \\
\Leftrightarrow x^2 = \frac{384}{6}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(-4(-6x^2+5)=-(-23x^2+20) \\ \Leftrightarrow 24x^2-20=23x^2-20 \\
\Leftrightarrow 24x^2-23x^2=-20+20 \\
\Leftrightarrow x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{1}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-13x^2+7=-8x^2+7 \\ \Leftrightarrow -13x^2+8x^2=7-7 \\
\Leftrightarrow -5x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-5}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-3(5x^2-6)=-(8x^2+1557) \\ \Leftrightarrow -15x^2+18=-8x^2-1557 \\
\Leftrightarrow -15x^2+8x^2=-1557-18 \\
\Leftrightarrow -7x^2 = -1575 \\
\Leftrightarrow x^2 = \frac{-1575}{-7}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(4(-10x^2-3)=-(34x^2+108) \\ \Leftrightarrow -40x^2-12=-34x^2-108 \\
\Leftrightarrow -40x^2+34x^2=-108+12 \\
\Leftrightarrow -6x^2 = -96 \\
\Leftrightarrow x^2 = \frac{-96}{-6}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(3x^2+300=0 \\
\Leftrightarrow 3x^2 = -300 \\
\Leftrightarrow x^2 = \frac{-300}{3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-4(9x^2+3)=-(28x^2+12) \\ \Leftrightarrow -36x^2-12=-28x^2-12 \\
\Leftrightarrow -36x^2+28x^2=-12+12 \\
\Leftrightarrow -8x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-8}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-3x^2-588=0 \\
\Leftrightarrow -3x^2 = 588 \\
\Leftrightarrow x^2 = \frac{588}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(7x^2-219=8x^2+6 \\ \Leftrightarrow 7x^2-8x^2=6+219 \\
\Leftrightarrow -x^2 = 225 \\
\Leftrightarrow x^2 = \frac{225}{-1} < 0 \\
V = \varnothing \\ -----------------\)
- \(-6x^2-6=0 \\
\Leftrightarrow -6x^2 = 6 \\
\Leftrightarrow x^2 = \frac{6}{-6} < 0 \\
V = \varnothing \\ -----------------\)
- \(-6x^2-14=-8x^2-6 \\ \Leftrightarrow -6x^2+8x^2=-6+14 \\
\Leftrightarrow 2x^2 = 8 \\
\Leftrightarrow x^2 = \frac{8}{2}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)