Answer:
Step-by-step explanation:
Let E be the set of all even positive integers in the universe Z of integers,
i.e
E = {2,4,6,8,10 ....∞}
be the characteristic function of E.
∴
For XE(2)
since x is an element of E (i.e the set of all even numbers)
For XE(-2)
since - 2 is less than 0 , and -2 is not an element of E
For { x ∈ Z: XE(x) = 1}
This can be read as:
x which is and element of Z such that X is also an element of x which is equal to 1.
∴
E = {2,4,6,8,10 ....∞}
x(t) = 20t
y(t) = 40t - 5t^2
Since we are only interested in comparing the two at time t = 5 seconds, we plug in 5 everywhere we see the variable t and then compare x and y
x(5) = 20(5) becomes x(5) = 100
y(5) = 40(5) - 5(5)^2 becomes y(5) = 200 - 125 and then y(5) = 75
The ratio of y to x can be expressed as: y/x, so we can say the ratio is equal to 75/100 or 0.75
Answer: 0.75
Step-by-step explanation:
2x = x1.2^n
2 = 1.2^n
log1.2(2) = n
log10(2)/log10(1.2) = n = 3.801784017...
so, rounded to the next whole year it takes 4 years.
