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Quadratic Formula
Solving Equations by the Quadratic Formula & Quadratic Methods
Question | Answer |
---|---|
Quadratic formula X= | X = -b± √ b2-4ac / 2a |
Discriminant | b2-4ac. Positive = 2 real solutions. Zero= 1 real solution. Negative= 2 complex but not real solutions. |
x2+7x+4 | -2+√ 11, -2-√ 11. Use Quadratic equation to solve |
(2/5)y2+(1/5)y+(3/5)=0 | (-1+i√ 23)/4, (-1-i√ 23)/4. Use quadratic equation to solve |
6=4x-5x2 | 2 complex but not real solutions. Remember that if the answer is negative there are 2 complex but not real solutions. |
m2+5m-14=0 | m=2 or m= -7. Use quadratic equation to solve |
√ 144x=x+20 | x=100 or x=4 |
4x=√ (31+2) | x=2. Check values of x to find the correct answer(s) |
p4-p2-2=0 | p=√ 2, -√ 2, i,-i |
x2-4=0 | 16. Use the discriminant. |
(p+4)2=6(p+4)-8 | p=0 or p=2. Let (p+4)=x, then don't forget to plug the values of x back into the original equation to find the p values. Check. |