Answer:
- a
- b
- b
- b
- c
- a
- b
- (a) [tex]7^{4}[/tex] (b) [tex](\frac{4}{9}) ^{17}[/tex] (c) [tex]4^{-4}[/tex] (d) [tex]8^{-3}[/tex]
Step-by-step explanation:
1. The moment he started: 3 bacteria
1st hour: 3*2 bacteria = 3*[tex]2^{1}[/tex] bacteria
2nd hour: 3*2*2 bacteria = 3*[tex]2^{2}[/tex] bacteria
3rd hour: 3*2*2*2 bacteria = 3*[tex]2^{3}[/tex] bacteria
etc.
Each hour the number of bacteria multiplies by 2 (the power of 2 is increased by 1), therefore, [tex]B=3*(2)^{n}[/tex]
2. Exponential function has the form of [tex]f(x)=ab^{x}[/tex]
if a is greater than 0 and b is greater than 1, then it's exponential growth.
The answer is:
[tex]y=4^{x}[/tex] (4 > 1)
3. If smth increases by 2.5% each time, that means that at first you had 100% and then it became 100%+2.5% = 102.5%. So each time we multiply the value by 1.025 (100*1.025=102.5).
4. Linear equation form: [tex]y=ax+b[/tex]
Quadratic equation form: [tex]y=ax^{2} + bx + c[/tex]
Exponential equation form: [tex]y=ab^{x}[/tex]
In this case, a = 3.8, b = -5.5, c = -4.8
5. (a) square root
(b) linear
(c) exponential
(d) quadratic
6. Each year the car's worth is multiplied by 0.82 (82%). Therefore, after n years, the value will be: V = 27 500 * [tex]0.82^{n}[/tex]
7. Neither first, nor second differences are constant in case of an exponential relation, because we do not add but multiply.
Ex. [tex]y=2^{x}[/tex]
values: 1 2 4 8 16 32...
1st diff: 1 2 4 8 16...
2nd diff: 1 2 4 8...
8. (a) [tex]7^{11} / 7^{7} = 7^{11-7} = 7^{4}[/tex]
(b) [tex](\frac{4}{9})^{12} *(\frac{4}{9})^{5} =(\frac{4}{9} )^{12+5}=(\frac{4}{9})^{17}[/tex]
(c) [tex]4^{11} / (4^{5})^{3} =4^{11} / 4^{5*3}=4^{11} /4^{15}=4^{11-15}=4^{-4}[/tex]
(d) [tex]8^{-6}*8^{3}=8^{-6+3}=8^{-3}[/tex]
