Core Connections Algebra 2, 2013
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Core Connections Algebra 2, 2013 View details
1. Section 8.1
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Exercise 39 Page 382

Practice makes perfect
a To find the degree of a polynomial, we need to find the highest exponent of a variable in it. Consider the given function.

P(x)=0.08x^2+28x In this case, the highest exponent is 2. This is the degree of the given polynomial function.

b Similarly as in Part A, let's find the highest exponent of a variable.

y=8x^2-1/7x^5+9 We can see that the highest exponent is 5. This is the degree of the given polynomial.

c Examining the given polynomial function, we can see that it is in factored form.
f(x)=5(x+3)(x-2)(x+7)We can find the highest exponent of a variable by rewriting the polynomial in standard form. To do so, we can use the Distributive Property.
f(x)=5(x+3)(x-2)(x+7)
f(x)=(5x+15)(x-2)(x+7)
f(x)=(x(5x+15)-2(5x+15))(x+7)
â–Ľ
Distribute x & -2
f(x)=(5x^2+15x-2(5x+15))(x+7)
f(x)=(5x^2+15x-10x-30)(x+7)
f(x)=(5x^2+5x-30)(x+7)
f(x)=x(5x^2+5x-30)+7(5x^2+5x-30)
â–Ľ
Distribute x & 7
f(x)=5x^3+5x^2-30x+7(5x^2+5x-30)
f(x)=5x^3+5x^2-30x+35x^2+35x-210
f(x)=5x^3+40x^2+5x-210
Now that we have rewritten the polynomial in standard form, we can see that its highest exponent is 3. f(x)=5x^3+40x^2+5x-210 Therefore, the degree of the polynomial is 3.
d Once again, the given polynomial function is in factored form.
y=(x-3)^2(x+1)(x^3+1) To determine its degree, we will rewrite it in standard form. Note that the first factor is a square of a binomial. This allows us to write is as a trinomial.
y=(x-3)^2(x+1)(x^3+1)
y=(x^2-2(x)(3)+3^2)(x+1)(x^3+1)
y=(x^2-6x+3^2)(x+1)(x^3+1)
y=(x^2-6x+9)(x+1)(x^3+1)
Now, we can again use the Distributive Property to rewrite the polynomial in standard form.
y=(x^2-6x+9)(x+1)(x^3+1)
y=(x(x^2-6x+9)+1(x^2-6x+9))(x^3+1)
â–Ľ
Distribute x & 1
y=(x^3-6x^2+9x+1(x^2-6x+9))(x^3+1)
y=(x^3-6x^2+9x+x^2-6x+9)(x^3+1)
y=(x^3-5x^2+3x+9)(x^3+1)
y=(x^3(x^3-5x^2+3x+9)+1(x^3-5x^2+3x+9))
â–Ľ
Distribute x^3 & 1
y=(x^6-5x^5+3x^4+9x^3+1(x^3-5x^2+3x+9))
y=x^6-5x^5+3x^4+9x^3+x^3-5x^2+3x+9
y=x^6-5x^5+3x^4+10x^3-5x^2+3x+9
Finally, we can see that its highest exponent is 6. y=x^6-5x^5+3x^4+10x^3-5x^2+3x+9 Therefore, the degree of the polynomial is 6.