Lesson Title - Loudoun County Public Schools



Name/Period: _______________________________________Unit icHomeworkHW √On-TimeFeb. 10 (B)8.3Exponents and PowersZero and Negative ExponentsPage 506: 2-38, evenEssential Question: How can you simplify expressions using exponents?Feb. 12 (B)8.1Multiplying Powers with the Same BasePage 492: 3-18Essential Question: How can you simplify expressions using exponents?Feb. 17 (B)8.2Quiz #1Multiplication and Division Properties of ExponentsPage 492: 19-37, oddPage 499: 3-49, oddEssential Question: How can you simplify expressions using exponents?Feb. 19 (B)8.4Scientific NotationApplications of Scientific NotationPage 515: 1-47, odd AND 51 and 52Essential Question: How can you use the graphing calculator to evaluate expressions and equations using scientific notation?Feb 23 (B)2.711.2Quiz #2Radicals: Square roots & cube rootsReal Number SystemExpress square roots and cube roots in simplest radical formpp. 723: 3-25Essential Question: How do we express the square root/cube root of a function in its simplest form?Feb. 25 (B)Unit ReviewReview PacketStudy, study, studyEssential Question: How can we simplify expressions using exponents, scientific notation, and square/cube roots?Feb. 29 (B)Unit TestEssential Question: How can we simplify expressions using exponents, scientific notation, and square/cube roots?Exponents & PowersYou can use powers to shorten how you represent repeated multiplication, such as:2 x 2 x 2 x 2 x 2 x 226A power has two parts, a base and an exponent. The exponent tells you how many times to use the base as a factor.Examples.5x2(5x)3What is the exponent?What is the base?You simplify a numerical expression when you replace it with its single numerical value. For example, the simplest form of 23 is 8 (2 x 2 x 2).Examples. What is the simplified form of the expression?107=10?10?10?10?10?10?10 =10,000,000 (0.2)5=Practice. What is the simplified form of the expression?1. 52 2. 253. 35 4. (?)4 Zero and Negative ExponentsProperties of Zero as an Exponent: For every nonzero number, x, x0 = 1.Examples.40 = 1(-3)0 = 15.140 = 1Properties of Negative Exponents: For every nonzero number, x, and integer, n, x-n = 1/xnExamples.7-3=173(-5)-2=1-52Note that this is specific to all numbers EXCEPT zero as the base. WHY???Remember that an algebraic expression is in its simplest form when powers with a variable base are written only with positive exponents. Therefore, when simplifying expressions, we follow the Properties of Zero and Negative Exponents.Examples. What is the simplified form of each expression?9-2=(-3.6)0= 4-3= -50= (-4)-2= 6-1=5a3b-2=1x-5= n-5m2= 9r-2t-332g-4h2=4c-3b= 5a-2b0=Practice. What is the simplified form of each expression?(3/5 )-1= 180= 3-4= 5g-3h4= 2-2x-3y-24-2z-3w2= 6a-2b-33c-5=Multiplying Powers with the Same BaseTo multiply powers with the same base, add the exponents.43?45=43+5=48b7?b-4=b7+(-4)= b7-4=b3 Let’s prove it….34?32Is the same as….3?3?3?3?(3?3)Which is the same as….3?3?3?3?3?3Which is the same as….36When variable factors have more than one base, be careful to combine only those powers with the same base.When working with variables as the base, be sure to multiply the coefficients when simplifying the expression.Examples. What is the simplified form of each expression?124?123=124+3Add the exponents of the powers with the same base = 127Simplify the exponent =358,318,808Simplify(-5)-2?(-5)7=9-3?92?96=4z5?9z-12=4?9(z5?z-12)Commutative and associative properties of multiplication =36(z5+-12)Multiply the coefficients. Add the exponents of the powers with the same base. =36z-7Simplify the exponent. =36z7Rewrite using a positive exponent.2a?9b4?3a2= 5x4?x9?3x=Practice. What is the simplified form of each expression?-53?-5-5?-5-2?-55=-4c3?7d2?2c-2j2?k-2?12j=Multiplication & Division Properties of ExponentsYou can use repeated multiplication to simplify a power raised to a power.(x5)2 = x5 ? x5 = x5 + 5 = x10……………which is equivalent to x5?2 = x10Notice that (x5)2 = x5 ? 2. Raising a power is the same as raising the base to the product of the exponents.Examples. What is the simplified form of the expression?(n4)7 = y3(y5)-2 = (n5)2(4mn-2)3 = (x-2)2(3xy5)4 =Practice. What is the simplified form of the expression?(p5)4 = 7(m9)3 = (3g4)-2 = (x-2)2(3xy5)4 = (6ab)3(5a-3)2 = To divide powers with the same base, subtract the exponents.8153401530350066294016256000510540153035009010652622550074866527178000605790262255004543=4?4?4?4?44?4?4=42………….notice that this is equivalent to 45-3Examples. What is the simplified form of each expression?x8x6=d3d9=a-3b7a5b2=Practice. What is the simplified form of each expression?y5y4=k6j2kj5=x4y-1z8x4y-5z= To raise a quotient to a power, raise the numerator AND the denominator to the power and simplify.Examples.(ab)n=anbn(35)3 = (xy)5 =(2x6y4)-3 =Practice.y3y10=(x43)3 =(a5b)-2 = (3x25y4)-4 = Scientific NotationScientific notation is a shorthand way to write numbers using powers of 10. It is used to write very large or very small numbers more easily.Why do you think it is called Scientific Notation?A number in scientific notation is written as the product of two factors in the form of a × 10n, where n is an integer and 1 < |a| < 10.Examples of Scientific Notation.8.3 × 103 4.12 × 1022 7.1 × 10-22 Are these numbers in scientific notation?0.23 × 10-32.3 × 107 9.3 × 1009With scientific notation, you use positive exponents to write numbers greater than 1. For example, 1,430,000,000 = 1.43 × 1,000,000,000 = 1.43 × 109.A shortcut to accomplish this is as follows:You need to create your a which is between 1 and 10. Therefore, you need to move the decimal to the left to create an appropriate a. In this case, you move the decimal 9 places to the left.294767026670001,430,000,000Use the number of places that you used the decimal as your positive exponent to the base of 10. Again, in this case, you use 9 as your exponent.109Now you can write the number in scientific notation.1.43 × 109For numbers less between 0 and 1, you use negative exponents to write the number in scientific notation. For example, 0.0000000001 = 1 × 10-10A shortcut to accomplish this is as follows:You need to create your a which is between 1 and 10. Therefore, you need to move the decimal to the right to create an appropriate a. In this case, you move the decimal 10 places to the right.0.000000000129476702667000Use the number of places that you used the decimal as your negative exponent to the base of 10. Again, in this case, you use -10 as your exponent.10-10Now you can write the number in scientific notation.1 × 10-10To convert numbers from scientific notation to standard notation, you do the opposite:If the exponent is positive, move the decimal to the right.5.5 × 106 = 5,500,000If the exponent is negative, move the decimal to the left.3.1 × 10-3 = 0.0031Practice. What is each number written in scientific notation?678,000 = 0.000032 = 51,400,000 = 0.0000007 =What is each number written in standard notation?5.23 × 107 = 4.6 × 10-5 =2.09 × 10-4 = 3.8 × 1012 =Comparing and Ordering Numbers in Scientific NotationTo compare and order number in scientific notation:Compare the powers of 10.Order the numbers based on the powers.If ordering least to greatest, order the powers least to greatest.If ordering greatest to least, order the powers greatest to least.If numbers have the same power of 10, then compare the decimals.If ordering least to greatest, order the decimals least to greatest.If ordering greatest to least, order the decimals greatest to least.Example.The earth’s four major oceans with their corresponding surface areas are:Arctic = 1.41× 107, Atlantic = 1.06 × 108, Indian = 7.49 × 107, and Pacific = 1.8 × 108.What is the order of the oceans from least to greatest surface area?Practice. What is the order of the following parts of an atom from least to greatest mass?neutron: 1.675 × 10-24 g; electron: 9.109 × 10-28 g, proton: 1.673 × 10-24 g Using the Graphing Calculator for Scientific NotationYou can use your graphing calculator to work with numbers in scientific notation. The E on the calculator’s readout stands for exponentiation. The readout 1.35E8 means 1.35 × 108, or 135,000,000. The EE key lets you input an exponent for a power of 10. So to enter 4 × 106, you enter 4 EE 6.You can work with your calculator in either Normal Mode or Scientific Mode to work with scientific notation. To change the mode on the calculator, select MODE and move the cursor to the right or left to choose either NORMAL or SCI.In Normal Mode: If a problem is already expressed in scientific notation, you may simply enter the problem on the home screen in Normal Mode to arrive at the answer. Note that the answer will be displayed in standard format unless the answer cannot be displayed in 10 digits or if the absolute value is less than 0.001.Example. With the calculator in Normal Mode, enter 4.726 × 10 -3.4.726 *10^-3 OR 4.726 EE-3The answer is .004726Now enter 4.726 × 10-12. What is displayed this time? What does the E mean?In Scientific Mode: If a problem asks for the answer to be expressed in scientific notation, you will want to change the Mode to SCI and your answers will be displayed in scientific notation, regardless of the number of decimals.Example. With the calculator in Normal Mode, enter 4.726 × 10 -3.4.726 *10^-3 OR 4.726 EE-3The answer is 4.726E-3Now enter 9.3 × 107. What is displayed this time?Calculations Using Scientific NotationThe properties of exponents are used when calculating with numbers written in scientific notation.Examples. Write answers in scientific notation.(2.5 × 10-3) ? (3.0 × 105)(6.3 × 105) ? (1.2 × 103)2.5 ?3.0 × 10-3?1057.5 × 1028.4 × 1092.0 × 105=8.42.0×109105 1.5×105÷(8.0×10-2) =4.2 ×104(2.1 × 104)2(5.0 × 106)3(2.1)2 × (104)24.41 × 108 Practical Problems Using Scientific NotationWrite out the steps you need to solve each problem and then solve. Using a graphing calculator is highly recommended.The mass of one molecule of water is 2.99 x 10-23 g. If a cylinder contains 3.0 x 1050 molecules of water, what is the mass of the water in the container?The diameter of Earth is 1.2756 x 104 km and the diameter of our sun is 1.39 x 106 km. What is the ratio of the diameter of earth to the diameter of our sun?The average distance from the sun to Mars is 2.28 x 108 km. The speed of light is 3 x 105 km/s. How long does it take for light from the sun to reach Mars?The mass of Mercury is 3.3 x 1023. The mass of Venus is 4.87 x 1024. The mass of Earth is 5.98 x 1024. What is the combined mass of these three planets?The average distance from the sun to Jupiter is 7.78 x 108 km. The average distance from the sun to Saturn is 1.43 x 109 km. How much farther from the sun is Saturn than Jupiter?California has an area of approximately 1.56 x 105 square miles. California has a population of about 2.98 x 107. How many people are there per square mile? Squares, Cubes and RootsPerfect squares are the product of multiplying two identical numbers – taking a number to the power of 2 (x2). Fill in the table of perfect squares:x123456789101112x2The square root of a number is one of the two identical factors of the number. {Identical Twins!}Positive numbers have a positive square root and a negative square root.1625125Negative numbers do not have a real square roots because the square of a number is never negative.-4-81-169Practice.64-121-100Taking a number to the 3rd power (x3) is called finding the cube of that number. Fill in the table of perfect cubes.x12345678910x3The cube root of a number is one of the three identical factors of the number. {Identical Triplets!} Positive numbers have positive cube roots.393125364Negative numbers have negative cube roots.3-10003-643-8Practice.3-273216-3-9When simplifying radical expressions, we look for identical twins (square roots) and identical triplets (cube roots). After identifying all identical items, any “left-overs” remain under the radical.Examples.625184x2y535438139x7y6Practice.100v3375r928x3y33250j3k63192x180Properties of ExponentsAll Properties of Exponents apply only to non-zero bases.Zero Exponent Propertya0=1Any base with the power of 0 is equal to 1.Negative Exponent Propertya-b=1ab 1a-b= abA negative exponent means that you create the multiplicative inverse of the base with a positive exponent.Property of Powers Propertyab?ac=ab+cWhen you multiply two powers with the same base, you add the exponents.Quotient of Powers Propertyabac=ab-cWhen you divide two powers with the same base, you subtract the exponents.Power of a Product Property(ab)c= acbcTo find the power of a product, either find the power of each factor and then multiply or multiply the factors and raise the product to the power.Power of a Quotient Property(ab)c=acbcTo find the power of a quotient, either find the power of each factor and then divide or divide the factors and raise the quotient to the power.Power of a Power Property(ab)c= abcTo find a power of a power, multiply the exponents. ................
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