Do Now 5/10/11Do Now 5/10/11 Take out HW from last night.Take out HW from last night.

Text p. 456, #16-40 evensText p. 456, #16-40 evens

Copy HW in your planner.Copy HW in your planner. Text p. 456, #42-64 evensText p. 456, #42-64 evens Quiz sections 9.1 & 9.2 FridayQuiz sections 9.1 & 9.2 Friday

In your journal, solve the following equations. In your journal, solve the following equations.

3214

w3165 c

HomeworkHomework Text p. 456, #16-40 evens Text p. 456, #16-40 evens

16) ±5 18) ±9 20) ±32 22) ±40 24) 7 feet 26) -11

28) ±4 30) ±16 32) -3 34) -3.2 36) 10.5 38) 36.4 40) 2.6

ObjectiveObjective SWBAT simplify expressions with SWBAT simplify expressions with

radicals and solve equations using radicals and solve equations using square rootssquare roots

Section 9.1 “Square Roots”Section 9.1 “Square Roots”

If If b² = ab² = a then then bb is the is the square rootsquare root of of aa..

TheThe SQUARE ROOTSQUARE ROOT of a number is of a number is denoted by the symbol , which denoted by the symbol , which is called ais called a radicalradical. .

39 radicandradicand

Evaluate the ExpressionEvaluate the Expression

√ √ a – b a – b

PPEEMDMDASAS

66

a = 48, a = 48, b = 12b = 12

√ √ 4848 – – 1212

√ √ 3636

Evaluate the ExpressionEvaluate the Expression

-3√ ab -3√ ab

PPEEMDMDASAS

-3(24)-3(24)

a = 48, a = 48, b = 12b = 12

-3√ (-3√ (4848)()(1212))

-3√ 576-3√ 576

-72-72

Try it out…Evaluate the Expression

84 2 ba22 ba

812

a = 11b = 5

a = 3b = 7

To solve an equation with an x², you need

to ISOLATE the x² on one side and then take the square root of both sides of the equation.

,ba If 22 ba then

22 ba If then22 ba

Solve Equations Solve Equations Using Square RootsUsing Square Roots

Equation

Like a scale, the Like a scale, the left side and right left side and right side must be the side must be the same in order to be same in order to be balanced!balanced!

+ 8 = 20+ 8 = 20Left side Right side

ss

‘‘s’ has to be 6 in order s’ has to be 6 in order to make the equation to make the equation balanced.balanced.

22Remember th

is?

Equation-mathematical sentence

with an equal sign

Like a scale,Like a scale,both sides must be both sides must be EQUALEQUAL in order in order to be balanced.to be balanced.

Remember this?

Solving Equations with x²…

x² + 5 = 21x² + 5 = 21- 5 5 -5 5

x² = 16x² = 16

Isolate the variable! Get ‘x²’ by itself.Isolate the variable! Get ‘x²’ by itself.

To get the ‘x²’ byTo get the ‘x²’ by itself first get rid itself first get rid of “adding 5.” of “adding 5.”

Do the opposite.Do the opposite.““Subtract 5.”Subtract 5.”

Whatever you do toWhatever you do toone side of the equationone side of the equationyou must do the other side.you must do the other side.

x = ±4x = ±4To get the ‘x’ byTo get the ‘x’ by itself get rid itself get rid of the “square” by of the “square” by using the square root. using the square root.

√ √

Solving Equations with x²…Solving Equations with x²…

3x² - 7 = 18 3x² - 7 = 18 +7 +7 +7 +7

3x² = 253x² = 2533 3 3

x² = 8.3x² = 8.3√ √ x = ±2.9x = ±2.9

Try it out…Round your solutions to the nearest tenth

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2

w3165 2 c

5.8w2.2c

HomeworkHomework Text p. 456, #42-64 evens Text p. 456, #42-64 evens