Answer:
(r o g)(2) = 4
(q o r)(2) = 14
Step-by-step explanation:
Given
Solving (a): (r o q)(2)
In function:
(r o g)(x) = r(g(x))
So, first we calculate g(2)
Next, we calculate r(g(2))
Substitute 9 for g(2)in r(g(2))
r(q(2)) = r(9)
This gives:
{
Hence:
(r o g)(2) = 4
Solving (b): (q o r)(2)
So, first we calculate r(2)
Next, we calculate g(r(2))
Substitute 3 for r(2)in g(r(2))
g(r(2)) = g(3)
Hence:
(q o r)(2) = 14
Answer:
There are 80 marks in total.
Step-by-step explanation:
Let the number of total marks be 
.
The percentage score of the student can be written as the ratio
.
However,
.
Equating the two:
.
Cross-multiply (that is: multiple both sides by 
, the product of the two denominators) to get
.
.
In other words, there are 80 marks in total.
Answer:
2,674.14 g
Step-by-step explanation:
Recall that the formula for radioactive decay is
N = N₀ e^(-λt)
where,
N is the amount left at time t
N₀ is the initial amount when t=0, (given as 42,784 g)
λ = coefficient of radioactive decay
= 0.693 ÷ Half Life
= 0.693 ÷ 18
= 0.0385
t = time elapsed (given as 72 years)
e = exponential constant ( approx 2.7183)
If we substitute these into our equation:
N = N₀ e^(-λt)
= (42,787) (2.7183)^[(-0.0385)(72)]
= (42,787) (2.7183)^(-2.7726)
= (42,787) (0.0625)
= 2,674.14 g
One way to do this is use the fact that the exterior angles of all polygons add up to 360 degrees
So an exterior angle of a regular octagon = 360 / 8 = 45 degrees.
So each interior angle = 180 - 45 = 135 degrees
so total measure of all angles in octagon = 8 * 135 = 1080 degrees
