Answers
1. 1,364
2. x⁴ + 2x - 6
3. x⁵ - 5x⁴ + 4x³ - x² + 5x - 4
4. x⁴ - 7x³ - 21x² + 63x -108
5. a(n-1) + 1.4
6. 3/(2× 2ⁿ⁻¹)
Step-by-step explanation
Q1
Σ4ⁿ = 4¹ + 4² + 4³ + 4⁴ + 4⁵
= 4 + 16 + 64 + 256 + 1024
= 1,364
Q2. What is (f−g)(x)?
f(x)=x4−3x2+5x−7
g(x)=x3−3x2+3x−1
(f−g)(x) = (x⁴−3x²+5x−7
) - (x³−3x²+3x−1)
=x⁴ + 2x - 6
3. What is (f⋅g)(x)?
f(x)=x2−5x+4
g(x)=x3−1
(f⋅g)(x) = (x³−1)(x²−5x+4
)
= x⁵ - 5x⁴ + 4x³ - x² + 5x - 4
4. Let f(x)=x2−9 and g(x)=x2−7x+12 .
What is (fg)(x)?
(fg)(x) = (x²−9)(x²−7x+12)
= x⁴ - 7x³ - 12x² - 9x² + 63x -108
= x⁴ - 7x³ - 21x² + 63x -108
5. What is the recursive rule for the sequence?
4.4, 5.8, 7.2, 8.6, 10, …
5.8 = 4.4 = 1.4, 10 - 8.6 = 1.4 The sequence is an AP where the common difference is 1.4 and the first term a is 4.4.
We and 1.4 to the previous term in order to get the next term.
an = a(n-1) + d
= a(n-1) + 1.4
6. Enter the explicit rule for the geometric sequence.
3/2, 3/4, 3/8, 3/16, 3/32, …
common ratio r, = 4/3 ÷3/2 = 1/2
First term a, = 3/2
an = arⁿ⁻¹
= (3/2)(1/2)ⁿ⁻¹
= 3/(2× 2ⁿ⁻¹)