Do on New WS 9-5 Day 3 (with rads) Factor Solve 9.5 mini Quiz Tomorrow! Warm up Factor Solve What is the formula needed for completing the square? What number needs to be added to complete the square?

Example 1: Solve (by completing the square) Step 1, 2, 3 x2 + 4x – 9 = 0 + 9 +9 x2 + 4x = 9 x2 + 4x + _____ = 9 + ____ 4 4

Continued ex 1 Step 4, 5 x2 + 4x + _____ = 9 + ____ (x + 2)2 = 13 4 4

Continued… (ex 1) (x + 2)2 = 13 x + 2 = ± 13 -2 -2 x = -2 ± 13 Step 6 -2 -2 x = -2 ± 13 Final Answer

Look at Delta Math

Example 2: Solve (by completing the square) Step 1, 2, 3 x2 - 1 = -10x + 10x +10x x2 + 10x - 1 = 0 + 1 +1 x2 + 10x + _____ = 1 + ____ 25 25

Continued ex 2.. x2 + 10x + _____ = 1 + ____ 25 25 (x + 5)2 = 26 Step 4, 5 x2 + 10x + _____ = 1 + ____ (x + 5)2 = 26 25 25

Continued… (ex 2) (x + 5)2 = 26 x + 5 = ± 26 -5 -5 x = -5 ± 26 Step 6 -5 -5 x = -5 ± 26 Final Answer

Example 3: Which equation has the same solution? Step 1-4 only x2 – 16x +20 = -2 -20 -20 x2 – 16x = -22 x2 – 16x + _____ = -22 + ____ (x – 8)2 = 42 64 64 Final Answer

Example 4: Which equation has the same solution? Step 1-4 only x2 + 14x – 4 = -10 + 4 +4 x2 + 14x = -6 x2 + 14x + _____ = -6 + ____ (x + 7)2 = 43 49 49 Final Answer

Homework

Example 5: Solve 2 ways 1 1 x2 – 2x – 1 = 2 x2 – 2x – 1 = 2 Solve by FACTORING Solve by COMPLETING THE SQUARE x2 – 2x – 1 = 2 x2 – 2x – 1 = 2 + 1 +1 - 2 - 2 x2 – 2x = 3 x2 – 2x – 3 = 0 1 x2 – 2x + ___= 3 +___ 1 (x – 3)(x + 1)= 0 (x – 1)(x – 1)= 4 (x – 3) = 0 (x + 1)= 0 (x – 1)2 = 4 + 3 + 3 - 1 - 1 x – 1 = ± 2 +1 +1 x = 1 ± 2 x = 3 x = -1 x = 1 + 2 x = 1 - 2 x = 3 x = -1

Homework