10.2 Day 2: Quadratic Formula

10.2 Day 2:

Quadratic Formula

Learning Goal: I can solve quadratic equations by using the quadratic formula. ​

Multiple Choice

$$x^2+5x-6=0$$

• $$\left\{-6,\ 1\right\}$$

• $$\left\{-1,-6\right\}$$

• $$\left\{1,6\right\}$$

• No solution

Multiple Choice

$$2x^2+5x=8$$

• $$x=\frac{5+\sqrt{90}}{4}$$

• $$x=\frac{-5\pm\sqrt{\ 89}}{4}$$

• $$x=\frac{5-\sqrt{90}}{4}$$

• No solution

Multiple Choice

$$-4x^2+19x=21$$

• $$\left\{-\frac{7}{4},\ 3\right\}$$

• $$\left\{-\frac{7}{4},\ -3\right\}$$

• $$\left\{\frac{7}{4},\ 3\right\}$$

• No solution

​Discriminant

​Example 1a

​Example 1b

​Example 2a

​Example 2b

Multiple Choice

$$3x^2+2x-3=0$$

• $$x=\frac{-1\pm\sqrt{\ 10}}{3}$$

• $$x=\frac{1+\sqrt{\ 11}}{6}$$

• No solution

Multiple Choice

$$2x^2+3x+4=0$$

• $$x=\frac{-1\pm\sqrt{\ 10}}{3}$$

• $$x=\frac{1+\sqrt{\ 11}}{6}$$

• No solution

Multiple Choice

$$9x^2-18x+9=0$$

• $$x=\frac{-1\pm\sqrt{\ 10}}{3}$$

• $$x=1$$

• No solution

Multiple Choice

$$4x^2-x-4=0$$

• $$x=\frac{-1\pm\sqrt{65}}{8}$$

• $$x=1$$

• No solution