Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(2(-3x^2-8)=-(2x^2+52)\)
- \(4x^2-676=0\)
- \(17x^2-284=9x^2+4\)
- \(4(-10x^2-5)=-(34x^2+404)\)
- \(-4(-4x^2-5)=-(-9x^2-20)\)
- \(-3x^2+3=0\)
- \(2(-6x^2-9)=-(11x^2+118)\)
- \(-8x^2-392=0\)
- \(4(-2x^2+10)=-(11x^2-283)\)
- \(5(-10x^2+5)=-(42x^2+1327)\)
- \(4x^2+36=0\)
- \(-4x^2+603=2x^2+3\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(2(-3x^2-8)=-(2x^2+52) \\ \Leftrightarrow -6x^2-16=-2x^2-52 \\
\Leftrightarrow -6x^2+2x^2=-52+16 \\
\Leftrightarrow -4x^2 = -36 \\
\Leftrightarrow x^2 = \frac{-36}{-4}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(4x^2-676=0 \\
\Leftrightarrow 4x^2 = 676 \\
\Leftrightarrow x^2 = \frac{676}{4}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(17x^2-284=9x^2+4 \\ \Leftrightarrow 17x^2-9x^2=4+284 \\
\Leftrightarrow 8x^2 = 288 \\
\Leftrightarrow x^2 = \frac{288}{8}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(4(-10x^2-5)=-(34x^2+404) \\ \Leftrightarrow -40x^2-20=-34x^2-404 \\
\Leftrightarrow -40x^2+34x^2=-404+20 \\
\Leftrightarrow -6x^2 = -384 \\
\Leftrightarrow x^2 = \frac{-384}{-6}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(-4(-4x^2-5)=-(-9x^2-20) \\ \Leftrightarrow 16x^2+20=9x^2+20 \\
\Leftrightarrow 16x^2-9x^2=20-20 \\
\Leftrightarrow 7x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{7}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-3x^2+3=0 \\
\Leftrightarrow -3x^2 = -3 \\
\Leftrightarrow x^2 = \frac{-3}{-3}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(2(-6x^2-9)=-(11x^2+118) \\ \Leftrightarrow -12x^2-18=-11x^2-118 \\
\Leftrightarrow -12x^2+11x^2=-118+18 \\
\Leftrightarrow -x^2 = -100 \\
\Leftrightarrow x^2 = \frac{-100}{-1}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(-8x^2-392=0 \\
\Leftrightarrow -8x^2 = 392 \\
\Leftrightarrow x^2 = \frac{392}{-8} < 0 \\
V = \varnothing \\ -----------------\)
- \(4(-2x^2+10)=-(11x^2-283) \\ \Leftrightarrow -8x^2+40=-11x^2+283 \\
\Leftrightarrow -8x^2+11x^2=283-40 \\
\Leftrightarrow 3x^2 = 243 \\
\Leftrightarrow x^2 = \frac{243}{3}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)
- \(5(-10x^2+5)=-(42x^2+1327) \\ \Leftrightarrow -50x^2+25=-42x^2-1327 \\
\Leftrightarrow -50x^2+42x^2=-1327-25 \\
\Leftrightarrow -8x^2 = -1352 \\
\Leftrightarrow x^2 = \frac{-1352}{-8}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(4x^2+36=0 \\
\Leftrightarrow 4x^2 = -36 \\
\Leftrightarrow x^2 = \frac{-36}{4} < 0 \\
V = \varnothing \\ -----------------\)
- \(-4x^2+603=2x^2+3 \\ \Leftrightarrow -4x^2-2x^2=3-603 \\
\Leftrightarrow -6x^2 = -600 \\
\Leftrightarrow x^2 = \frac{-600}{-6}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)