Here are the solutions to the problems.
1. Find the degree of each polynomial
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a) 3xy4
Step 1: Identify the exponents of the variables.
The exponent of x is 1. The exponent of y is 4.
Step 2: Sum the exponents.
Degree =1+4=5.
The degree of the polynomial is 5.
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b) 10x2y3+z4
Step 1: Find the degree of each term.
For 10x2y3: sum of exponents is 2+3=5.
For z4: exponent is 4.
Step 2: The degree of the polynomial is the highest degree among its terms.
The highest degree is 5.
The degree of the polynomial is 5.
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c) Q(x)=7x6−4x4+2x3−x+1
Step 1: Identify the highest exponent of the variable x.
The exponents are 6,4,3,1,0 (for the constant term).
Step 2: The highest exponent is 6.
The degree of the polynomial is 6.
2. Determine which of the following expressions are polynomials. Give reasons for your answer.
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a) 3x3−2x+7
This is a polynomial.
Reason: All exponents of the variable x are non-negative integers (3,1,0).
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b) x1+4
This is not a polynomial.
Reason: The term x1 can be written as x−1, which has a negative exponent (−1). Polynomials must have only non-negative integer exponents.
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c) 5x1/2+x
This is not a polynomial.
Reason: The term 5x1/2 has a fractional exponent (21). Polynomials must have only non-negative integer exponents.
3. Find the remainder when the polynomial P(x)=2x3−5x2+4x−3 is divided by x−2.
Step 1: Apply the Remainder Theorem.
The Remainder Theorem states that if a polynomial P(x) is divided by x−c, the remainder is P(c).
In this case, P(x)=2x3−5x2+4x−3 and the divisor is x−2, so c=2.
Step 2: Evaluate P(2).
P(2)=2(2)3−5(2)2+4(2)−3
P(2)=2(8)−5(4)+8−3
P(2)=16−20+8−3
P(2)=−4+8−3
P(2)=4−3
P(2)=1
The remainder is 1.
4. Rewrite the polynomial in descending powers of x:3x+7x4−2x2+5.
Step 1: Identify the terms and their powers of x.
3x has power 1.
7x4 has power 4.
−2x2 has power 2.
5 is a constant term, which can be considered 5x0.
Step 2: Arrange the terms from the highest power of x to the lowest.
The order of powers should be 4,2,1,0.
7x4−2x2+3x+5
The polynomial in descending powers of x is 7x4−2x2+3x+5.
5. Given P(x)=2x3−5x2+4x−1, find the value of P(2).
Step 1: Substitute x=2 into the polynomial expression.
P(2)=2(2)3−5(2)2+4(2)−1
Step 2: Evaluate each term.
P(2)=2(8)−5(4)+8−1
P(2)=16−20+8−1
Step 3: Perform the additions and subtractions.
P(2)=−4+8−1
P(2)=4−1
P(2)=3
The value of P(2) is 3.