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University of Phoenix MTH 209 Algebra II. The FUN continues!. Chapter 4. What we are doing now is using all we have used so far and add a few complications like the concept of a root (square root, cube root, etc.). The big word for MTH 209 is a polynomial (poly = parrot)
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University of PhoenixMTH 209 Algebra II The FUN continues!
Chapter 4 • What we are doing now is using all we have used so far and add a few complications like the concept of a root (square root, cube root, etc.). • The big word for MTH 209 is a polynomial (poly = parrot) • (no… poly = many, nomial = number)
Section 4.1 • Remember the Product and Quotient Rules am * an = am+n And the zero exponent and a0 = 1
Taking what they throw at ya: Ex 1 page 256 • a) 23· 22 = 23+2 = 25 = 32 (calculator!) • b) x2 · x4 · x= x2 · x4 · x1=x7 • c) 2y3 ·4y8=(2)(4)y3y8=8y11 • d) -4a2b3(-3a5b9)=(-4)(-3) a2a5b3b9=12a7b12 **Ex. 7-18**
Zero Exponent Example 2 page 257 a) 50 = 1 b) (3xy)0 = 1 c) b0·b9=1 ·b9 c) 20+30 = 1+1=2 **Ex. 19-28**
Section 4.1 • Remember the Quotient Rules If then If n>m, then
More thrown at ya: Ex 3 page 258 • a) x7/x4= x7-4= x3 • b) w5/w3=w5-3=w2 • c) • d) **Ex. 29-40**
What about raising an exponent to and exponent? • Yes, we have to try to break it if we can! • What ABOUT raising an exponent to a power? • You MULTIPLY the exponents!
Power of a Power • (w4)3 = w4 w4 w4= w12 • Which is the same as w4*3 = w12 • Definition time:The Power Rule (am)n = amn
Example 4 page 259 • a) (23)8 = 23·8=224 • b) (x2)5=x2·5=x10 • c) 3x8(x3)6= 3x8(x3·6) = 3x8(x18) = 3x8+18=3x26 • d) **Ex. 41-50**
Now, to the power of a product. What if there is more than just x inside the ()’s? • For example: (2x)3=2x2x2x = 2*2*2*x*x*x= 23x3 (then do the math and get) 8x3 So the Power of a Product Rule (ab)n = anbn
Example 5 page 259 • a) (-2x)3=(-2)3x3=-8x3 • b) (-3a2)4= (-3)4 (a2)4 = 81a8 • c) (5x3y2)3 = 53(x3)(y2)3=124x9y6 **Ex. 51-58**
The power of a quotient • It is JUST what what you’d expect! • Raise the top and the bottom to the power by themselves, then work with it! For example
The Power of a Quotient • Where b does NOT equal 0
Example 6 • a) • b) • c) **Ex. 59-66**
All summed up! • Look to page 261 of your text for ALL these power rules to date summarized. • Use these for quizzes and tests!
Section 4.1 With your OWN hand • Definitions Q1-6 • Product rule Q7-18 • Zero exponents Q19-28 • Quotient Rule Q29-40 • Power Rule Q41-50 • Power of Product Q51-58 • Power of Quotient Rule Q59-66 • Simplify random stuff Q67-88 • Wordy Problems Q89-96 Remember… tan lines are ones with homework or group work problems in them
Section 4.2 Negative exponents (I’ve let you see them already- don’t tell anyone) • 1/x is the same as x-1 • So Negative Integral Exponents are defined as
What is one again? • a-n * an = a-n+n = a0 = 1
Example 1 page 265 • a) • b) • c)-9-2=-(9-2)= -1/92=-1/81 • d) **Ex. 7-16**
Some pitfalls • Watch the negative sign… • -5-2 = -(5-2) so the answer is –1/25 • Also if you see this… make it simpler
Helpful rules (pg 260) with negative powers… • a must be non-zero
Example 2 page 266 • a) • b) • c) • d) **Ex.17-26**
Rules for Integral Exponents • Just like positive exponents, if you multiply the numbers, add the exponents! • x-2 * x-3 = x-2+(-3) = x-5 • Or with division…
Example 3 Working it out… page 268 • a) b-3b5= b5-3=b2 • b) -3x-3 * 5x2 =-15x2-3= -15x-1 = -15/x • c) • d) **Ex. 27-42**
Example 4 page 268 • a) (a-3)2=a-3*2=a-6 • b) (10x-3)-2=10-2(x-3)-2 = 10-2x6= x6/100 • c) **Ex. 43-58**
Scientific Notation… or “how I learned to love large numbers” • We look at big numbers like 100000. and need to tell people later how many zeros we took out (who wants to write that many zeros anyway?). • 1.00000 we ‘hopped’ the decimal place 5 hops to the left (positive) direction • We write this as 1 x 105
Small numbers… • 0.0000000003 • We need to hop the decimal place to the right (negative direction) and place it to the right of the first integer. • 0x0000000003. We took 10 hops to the right • We code it as 3 x 10-10
nice examples • 10(5.32) = 53.2 • 102(5.32)=100(5.32)=532 • 103(5.32)=1000(5.32)=5320 and • 10-1(5.32)=.1(5.32)=.532 • 10-2(5.32)=.01(5.32)=.0532 • 10-3(5.32)=.001(5.32)=.00532
Example 6 page 270 • Write in standard notation • a) 7.02 x 106 = 7020000 = 7,020,000 • b) 8.13 x 10-5 = .0000813 **Ex. 65-72**
Example 7 page 271 • Write in Scientific Notation a) 7346200 it’s bigger than 10 so the exponent will be positive 7.3462 x 106 • 0.0000348 it’s less than 10 so the exponent will be negative 3.48 x 10-5 c) 135 x 10-12 it should start with 1.35 so we need to go positive 2 places changing it to 1.35x10-10 **Ex. 73-80**
Example 8 Computing with scientific notation (more exponents) page 272 • a) (3x106)(2x108) = 3*2*106*108=6x1014 • b)
Example 8c • (5x10-7)3=53(10-7)3=125 (10-21)=1.25(102)(10-21)= 1.25 x 10-19 **Ex. 81-92**
Example 9 page 272First Sci. Note. then math • a) (3,000,000)(0.0002) =3x106·2x10-4 = 6x102 b) (20,000,000)3(0.0000003) =8x1021 ·3x10-7 = 24x1014 need to move decimal 24. to 2.4 which is one to the right, or bigger! =24x1015**Ex. 93-100**
More pen to paper Section 4.2 • Definitions Q1-6 • Get rid of negative exponents Q7-26 • Write numbers in standard notation Q27-58 • Present Value Formula Q59-64 • Scientific Notation Q65-80 • Computations with S.N. Q81-108 • Word problems Q109-116 (Learning Team)
Section 4.3 • Polynomials…You have already seen them in Chapter 1 and 2 so don’t panic!
Poly-want a cracker? • What is a term? • 4x3 • -x2y3 • 6ab • -2 • xyza3
A polynomial is a set of those terms • A scrapbook of polynomials: • x2+5x+3 • 4x3+10x2+2x+100 • x+4
Simplify – the standard way • 4x3+x+(-15x2)+(-2) • We like to get rid of ( )’s • We like them in order of decreasing exponent and alphabetized if possible • The above becomes 4x3-15x2+x-2 • a2b + b2a + b3a2+ a3b2 simplifies to… • a3b2 + b3a2 + a2b + b2a
The degree of the polynomial • We label the terms by the number in the exponent • 4x3-15x2+x-2 • 3rd order term (or degree term) • 2nd order term (or degree term) • 1st order term (or degree term) • 0th order term (or degree term) this isalso called a constant [Try this on a calculator… if the power of the x with the constant is zero, then it is x0
You are constantly… • [Try this on a calculator… if the power of the x with the constant is zero, then it is x0 • What is 60? Or 10? Or even 10000? • So what is 10 * x0 ?
What’s in a coefficient? • 4x3-15x2+x-2 • The third order term’s coefficient is 4 • The second order term’s coefficient is –15 • The first order term’s coefficient is 1 • The constant is –2 (the coefficient to the zeroth order term)
Example 1 Got Coefficient? pg277 • What are the coefficients of x3 and x2 in each: • a) x3+5x2-6 which is _x3+5x2-6 • 1 and 5 • b) 4x6- x3 + x is the same as 4x6- x3 + 0x2 + x • So it’s –1 and 0 **Ex. 7-12**
Again… how we like to order them • We don’t like -4x2+1+5x+x3 • We do like x3-4x2+ 5x+ 1 • The coefficient of the highest order term (x3) is called the leading coefficient • The leading coefficient is 1 in this case • The order of the polynomial is the exponent (or power) of the HIGHEST term
Special Definitions • A monomial has only one term • x, x2 , 3 • A binomial has two terms • x+5 , or x3+4 • A trinomial has three terms (see a trend?) • 10x4+6x+100
Example 2 pg 277 • Identify each as a polynomial as either a monomial, binomial or trinomial and state it’s degree… • a) 5x2-7x3+2 is a trinomial of 3rd order (degree) • b) x43-x2 is a binomial of 43rd order (degree) • c) 5x=5x1 is a polynomial of degree 1 (order) • d) –12 is a monomial of degree 0 (order) • **Ex. 13-24**
Example 3 plug in the numberpg 278 • The value of a polynomial… • a) Find the value of –3x4-x3+20x+3 when x=1 -3(1)4-(1)3+20(1)+3 = -3-1+20+3 = 19 • b) The same equation when x=-2 -3(-2)4-(-2)3+20(-2)+3 = -48+8-40+3 = -77 **Ex. 25-32**
Example 4 another look pg279 a) and if P(x) = –3x4-x3+20x+3 and you’re told to find P(1) It’s the same as 3a) -3(1)4-(1)3+20(1)+3 = -3-1+20+3 = 19 b) If D(a)=a3-5 find D(0), D(1),D(2) 03-5=-5, 13-5=1-5=-4, 23-5=8-5=3 **Ex. 33-38**
Adding Polynomials • To add two polynomials, add the like terms • (You have done all this already as well!)