Sign in Start studying free

Asked in PPSC, FPSC and other one-paper exams (compiled from unofficial resources).

Sets & FunctionsFunctions and Relations

If $f(x) = x$, then $f(f(-1)) = ?$

A.$1$
B.$-1$Correct answer
C.$0$
D.$f(-1)$

Timed quizzes, instant results, track your progress — free

Practice these MCQs in the app

Quick fact: Since $f(x)=x$, applying $f$ twice to $-1$ yields $-1$.

Related MCQs

Let $f(x) = -3x^2 - 2x + 1$. Find $|f(1)|$.
If $F(x) + F(-x) = 6$, then the function is:
If $f(x) = -1$, what is $f(f(-1))$?
In a class, $\frac{3}{4}$ of the students do not know either Hindi or English. $\frac{1}{6}$ of the students know English and $\frac{1}{8}$ of the students know Hindi. What part of the students know both English and Hindi?
If the number of elements in set $A$ is $20$, in set $B$ is $30$, and the number of elements in the union of sets $A$ and $B$ is $40$, what is the number of elements in the intersection of sets $A$ and $B$?
In an examination, $25\%$ candidates failed in Mathematics and $20\%$ students failed in English. If $5\%$ students failed in both the subjects, find the percentage of students who passed in both the subjects.

Start studying free