Unit 5 Algebra Investigations

Notes 2.13: Use Square Roots to Solve Quadratic Equations

Lesson 3: Solving Polynomials

MM1A3a

VOCABULARY

Radicand-

Perfect Square-

(Ex 1) Solve quadratic equations

Solve the equation.

a) z2 – 5 = 4

b) r2 + 7 = 4

(Ex 2) Take square root of a fraction

Solve the equation 25k2 = 9.

Checkpoint

1) 3x^2=108

A.) 6

B.) 6, -6

C.) 36

D.) 36, -36

CHECKPOINT

1) 3x2 = 108

Checkpoint

2) t^2 + 17 = 17

CHECKPOINT

2) t2 + 17 = 17

Checkpoint

3) 81p^2=4

A.) 4/81, -4/81

B.) 2/9

C.) 4/81

D.) -2/9, 2/9

CHECKPOINT

3) 81p2 = 4

(Ex 3) Approximate solutions of a quadratic equation

Solve 4x2 + 3 = 23. Round the solutions to the nearest hundredth.

Checkpoint

4) 2x^2-7=9

A.) 8, -8

B.) 2.83, -2.83

C.) 4, -4

D.) 3.81, -3.81

CHECKPOINT

4) 2x2 – 7 = 9

Checkpoint

5) 6g^2 + 1 = 19

A.) 3, -3

B.) 1.83, -1.83

C.) 1.73, -1.73

D.) 18, -18

CHECKPOINT

5) 6g2 + 1 = 19

(Ex 4) Solve a quadratic equation

Solve 5(x + 1)2 = 30. Round the solutions to the nearest hundredth.

Checkpoint

6) 3(m - 4)^2 = 12

A.) 2, -2

B.) 4, -4

C.) 2, 6

D.) 0, 8

CHECKPOINT

6) 3(m – 4)2 = 12

Checkpoint

7) 4(a - 3)^2 = 32

A.) 5.828, 0.172

B.) 2.828, -2.828

C.) 8, -8

D.) 5, 11

CHECKPOINT

7) 4(a – 3)2 = 32

(Ex 5) Solve by squaring a radical

) 7 10

) 3 3 5

a x

b x x

Checkpoint

8) 0305 x

CHECKPOINT

0305 x8)

Checkpoint

9) 742 xx

CHECKPOINT

742 xx9)

ASSIGNMENT

p. 121 #2-24 (even)

p.148 #14, 16, 24