Three railway stations, A, B, and C, are situated on a straight railway route. Station B is at 30 km in the east from station A and station C is at 60 km in east from station A. A train, with a constant average velocity, starts from A and reaches B in 15 minutes, and reaches C in 30 minutes. Assuming that station A is the origin, find the following: a. The position of the train moving from station A to station B after 10 minutes.
b. The position of the train moving from station A to station B after 10 minutes, if station B is assumed to be the origin.
c. The position of the train moving from station A to station B after 10 minutes, if station C is assumed to be the origin.

a.) 20 km east

b.) 50 km west

c.) 80 km west

Explanation:

As given,

Railway station -     A            B              C

Distance(km) -       0            30             60

Starts from A , train reaches B be in 15 minutes

Starts from A , train reaches C be in 30 minutes

a.)

If A is origin

As train covers 30km = 15 minutes

⇒ 15 minutes = 30 km

    1 minute = km

⇒ 10 minutes = 2×10 = 20 km

∴ we get

The position of the train moving from station A to station B after 10 minutes = 20 km east

b.)

If B is origin then , the position of  the train moving from station A to station B after 10 minutes = 30 + 20  = 50 km west

( Because B is the origin , so firstly train go from B to A in 15 minutes ( 30 km ) then A to B in 10 minutes (20 km) )

c.)

If C is the origin then , the position of  the train moving from station A to station B after 10 minutes = 60 + 20  = 80 km west

( Because C is the origin , so firstly train go from C to A in 30 minutes ( 60 km ) then A to B in 10 minutes (20 km) )

we have been given a quadratic function and we need to restrict the domain such that it becomes a one to one function.

we know that vertex of this quadratic function occurs at (5,2).

further, we know that range of this function is .

if we restrict the domain of this function to either or , it will become one to one function.

let us know find its inverse.

upon interchanging x and y, we get:

let us now solve this function for y.

hence, the inverse function would be if we restrict the domain of original function to and the inverse function would be if we restrict the domain to .