(i) The simultaneous equations in a, b and c are a+b+c = 7 , 4a+2b+c = 9 & 9a+3b+c = 13
(ii) Expression for nth term = n²-n+7
The first three terms of the sequence are 7, 9, 13
nth term = an²+bn+c
If we put n = 1 then,
1st term = a(1)²+b+c
⇒ a+b+c = 7 ......(1)
If we put n = 2 then,
2nd term = a(2)²+b×2+c
⇒ 4a+2b+c = 9 ........(2)
3rd term = a(3)²+b×3+c
⇒ 9a+3b+c = 13 .......(3)
Multiplying 4 with (1) and subtract (2) from (1) we get,
(4a+4b+4c)-(4a+2b+c)=28-9
⇒ 4a+4b+4c-4a-2b-c=19
⇒ 2b+3c=19 .....(4)
Multiplying 9 with (1) and subtract (3) from (1) we get,
(9a+9b+9c)-(9a+3b+c)=63-13
⇒ 9a+9b+9c-9a-3b-c=50
⇒ 6b+8c=50
⇒ 3b+4c=25 .....(5)
Multiplying 3 with (4) and multiplying 2 with (5), then subtract (5) from (4),
3(2b+3c)-2(3b+4c)=57-50
⇒ 6b+9c-6b-8c=7
⇒ c = 7
From (5),
3b+28 = 25
⇒ 3b = -3
⇒ b = -1
From (1),
a+(-1)+7 = 7
⇒ a-1=0
⇒ a=1
So, nth term = n²-n+7
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The exponential function which has the greatest average rate of change over the interval [0, 2] is option B.
<h3>How to calculate the average rate of change?</h3>
Mathematically, the average rate of change between two (2) points can be calculated by using this expression;
For option A, we have:
when x = 0; when x = 2;
y = 3(1.6)^x y = 3(1.6)^x
y = 3(1.6)^0 y = 3(1.6)^2
y = 3. y = 7.68
ΔA = (7.68 - 3)/(2 -0) = 2.34.
For option B, we have:
ΔA = (9 - 4)/(2 -0) = 2.5.
For option C, the exponential function has a common ratio of 2.
ΔA = 2.
For option D, we have:
ΔA = (10 - 8)/(1 -0) = 2.
In conclusion, we can logically deduce that the exponential function which has the greatest average rate of change over the interval [0, 2] is option B i.e 2.5.
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Answer:
The twentieth term is 50.
Step-by-step explanation:
The equation that describes the arithmetic sequence describes it's "general term", which means that all the numbers in that sequence must follow that equation. For instance, if we want to find the first term of the sequence we must make a = 1 and we have:
a1 = 3*1 - 10
a1 = -7
Therefore to find the twentieth term we need to make n equal to 20. This is done below:
a20 = 3*20 - 10
a20 = 60 - 10
a20 = 50
The twentieth term is 50.
Answer:
no, it's a mcdonalds pepsi
Step-by-step explanation:
