Answers>Maths>IB>Article

Consider the functions f and g where f(x)=3x-5 and g(x)=x-2. (a) Find the inverse function for f. (b) Given that the inverse of g is x+2, find (g-1 o f)(x).

(a) In order to find the inverse of a function, it is easiest to swap x and y and solve for y. Here this would give, x=3y-5 => x+5=3y => (x+5)/3=y. Hence, f-1(x)=(x+5)/3. (b) Here it is important to remember the order in which to calculate the composition of a function and then slowly plugging in the required functions. This gives (g-1 o f)(x) = g-1(f(x))= g-1(3x-5)=3x-5+2=3x-3.

RM

Related Maths IB answers

All answers ▸

Show that the following system of equations has an infinite number of solutions. x+y+2z = -2; 3x-y+14z=6; x+2y=-5


What is a geometric sequence?


Which are the difference between polar and coordinate complex numbers?


Solve the differential equation csc(x)*dy/dx=exp(-y), given that y(0)=0. (Typical Math HL paper 3 question, Calculus optional topic)