1.
"The spending limit on John’s credit card is given by the function f(x)=15,000+1.5x"
means that if the monthly income of John is $ 5,000 ,he can spend at most
f(5,000)=15,000+1.5*5,000=15,000+ 7,500=22, 500 (dollars)
Or for example
if Johns monthly income is $8,000, then he can spend at most
f(8,000)=15,000+1.5*8,000=15,000+ 12,000=27,000 (dollars)
2.
Now, assume that the maximum amount that John can spend is y.
Then, y=15,000+1.5x
we can express x, the monthly income, in terms of y by isolating x:
y=15,000+1.5x
1.5x = y-15,000
X=y-15,000/1.5
thus, in functional notation, x, the monthly income, is a function , say g, of variable y, the max amount:
X=g(y) y-15000/1.5
since we generally use the letter x for the variable of a function, we write g again as:
G (x) x-15000/1.5
tells us that if the maximum amount that John can spend is 50,000 $, then his monthly income is 23,333 $.
3.
If John's limit is $60,000, his monthly income is
G(600,000)=60,000-15,000/ 1.5=45,000/1.5 =30,000
dollars.
Answer: $ 30,000
Remark: g is called the inverse function of f, since it undoes what f does.
instead of g(x), we could use the notation
Answer:
6p + 4d = 36
Step-by-step explanation:
If p = number of pins and d = number of major decisions, then the equation is 6p + 4d = 36.
Hope this helps!
Answer:
(x, y) = (-4, 15)
Step-by-step explanation:
The two equations have the same coefficient for y, so you can eliminate y by subtracting one equation from the other. Here the x coefficient is largest for the first equation, so it will work best to subtract the second equation.
(3x +y) -(2x +y) = (3) -(7)
x = -4 . . . . . . . . simplify
Now, we can find y by substituting this value for x.
2(-4) +y = 7
y = 7 +8 = 15 . . . . . add 8 to both sides of the equation
The solution is (x, y) = (-4, 15).
Substitute 
, so that 
, and
which is separable as
Integrate both sides with respect to 
. For the integral on the left, first split into partial fractions:
Solve for 
:
Replace and solve for 
:
Now use the given initial condition to solve for 
:
so that the particular solution is
