LFM Stats And Pure

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csat-suneung 2017 Q6 3 marks Derivative of an Inverse Function View
For the function $f ( x ) = x ^ { 3 } + x + 1$, let $g ( x )$ be its inverse function. What is the value of $g ^ { \prime } ( 1 )$? [3 points]
(1) $\frac { 1 } { 3 }$
(2) $\frac { 2 } { 5 }$
(3) $\frac { 2 } { 3 }$
(4) $\frac { 4 } { 5 }$
(5) 1
csat-suneung 2017 Q10 3 marks Graphical Interpretation of Inverse or Composition View
On the coordinate plane, when the graph of the function $y = \frac { 3 } { x - 5 } + k$ is symmetric with respect to the line $y = x$, what is the value of the constant $k$? [3 points]
(1) 1
(2) 2
(3) 3
(4) 4
(5) 5
csat-suneung 2017 Q14 4 marks Finding Parameters for Continuity View
For two functions $$\begin{aligned} & f ( x ) = \left\{ \begin{array} { c c } x ^ { 2 } - 4 x + 6 & ( x < 2 ) \\ 1 & ( x \geq 2 ) \end{array} , \right. \\ & g ( x ) = a x + 1 \end{aligned}$$ When the function $\frac { g ( x ) } { f ( x ) }$ is continuous on the entire set of real numbers, what is the value of the constant $a$? [4 points]
(1) $- \frac { 5 } { 4 }$
(2) $- 1$
(3) $- \frac { 3 } { 4 }$
(4) $- \frac { 1 } { 2 }$
(5) $- \frac { 1 } { 4 }$
csat-suneung 2018 Q4 3 marks Evaluate Composition from Diagram or Mapping View
The figure shows two functions $f : X \rightarrow Y , g : Y \rightarrow Z$. Find the value of $( g \circ f ) ( 2 )$. [3 points]
(1) 1
(2) 2
(3) 3
(4) 4
(5) 5
csat-suneung 2018 Q11 3 marks Derivative of an Inverse Function View
There are two functions $f ( x ) , g ( x )$ differentiable on the set of all real numbers. $f ( x )$ is the inverse function of $g ( x )$ and $f ( 1 ) = 2 , f ^ { \prime } ( 1 ) = 3$. If the function $h ( x ) = x g ( x )$, what is the value of $h ^ { \prime } ( 2 )$? [3 points]
(1) 1
(2) $\frac { 4 } { 3 }$
(3) $\frac { 5 } { 3 }$
(4) 2
(5) $\frac { 7 } { 3 }$
csat-suneung 2018 Q25 3 marks Convergence proof and limit determination View
A function $f ( x )$ satisfies $\lim _ { x \rightarrow 1 } ( x + 1 ) f ( x ) = 1$. When $\lim _ { x \rightarrow 1 } \left( 2 x ^ { 2 } + 1 \right) f ( x ) = a$, find the value of $20 a$. [3 points]
csat-suneung 2019 Q4 3 marks Evaluate Composition from Diagram or Mapping View
The figure shows a function $f : X \rightarrow X$. [Figure] What is the value of $f ( 4 ) + ( f \circ f ) ( 2 )$? [3 points]
(1) 3
(2) 4
(3) 5
(4) 6
(5) 7
csat-suneung 2019 Q9 3 marks Derivative of an Inverse Function View
When the inverse function of $f ( x ) = \frac { 1 } { 1 + e ^ { - x } }$ is $g ( x )$, what is the value of $g ^ { \prime } ( f ( - 1 ) )$? [3 points]
(1) $\frac { 1 } { ( 1 + e ) ^ { 2 } }$
(2) $\frac { e } { 1 + e }$
(3) $\left( \frac { 1 + e } { e } \right) ^ { 2 }$
(4) $\frac { e ^ { 2 } } { 1 + e }$
(5) $\frac { ( 1 + e ) ^ { 2 } } { e }$
csat-suneung 2019 Q17 4 marks Counting Functions or Mappings with Constraints View
The following is a process to find the number of functions $f$ such that the number of elements in the range of the composite function $f \circ f$ is 5, for the set $X = \{ 1,2,3,4,5,6 \}$ and the function $f : X \rightarrow X$.
Let the ranges of the function $f$ and the function $f \circ f$ be $A$ and $B$, respectively. If $n ( A ) = 6$, then $f$ is a bijection, and $f \circ f$ is also a bijection, so $n ( B ) = 6$. Also, if $n ( A ) \leq 4$, then $B \subset A$, so $n ( B ) \leq 4$. Therefore, we only need to consider the case where $n ( A ) = 5$, that is, $B = A$.
(i) The number of ways to choose a subset $A$ of $X$ with $n ( A ) = 5$ is (가).
(ii) For the set $A$ chosen in (i), let $k$ be the element of $X$ that does not belong to $A$. Since $n ( A ) = 5$, the number of ways to choose $f ( k )$ from the set $A$ is (나).
(iii) For $A = \left\{ a _ { 1 } , a _ { 2 } , a _ { 3 } , a _ { 4 } , a _ { 5 } \right\}$ chosen in (i) and $f ( k )$ chosen in (ii), since $f ( k ) \in A$ and $A = B$, we have $A = \left\{ f \left( a _ { 1 } \right) , f \left( a _ { 2 } \right) , f \left( a _ { 3 } \right) , f \left( a _ { 4 } \right) , f \left( a _ { 5 } \right) \right\} \cdots ( * )$. The number of cases satisfying (*) is equal to the number of bijections from set $A$ to set $A$, so $\square$ (다).
Therefore, by (i), (ii), and (iii), the number of functions $f$ we seek is $\square$ (가) $\times$ $\square$ (나) $\times$ $\square$ (다).
When the numbers that fit (가), (나), and (다) are $p , q , r$ respectively, what is the value of $p + q + r$? [4 points]
(1) 131
(2) 136
(3) 141
(4) 146
(5) 151
csat-suneung 2019 Q21 4 marks Polynomial Construction from Root/Value Conditions View
For a cubic function $f ( x )$ with leading coefficient 1 and a function $g ( x )$ that is continuous on the set of all real numbers, the following conditions are satisfied. (가) For all real numbers $x$, $f ( x ) g ( x ) = x ( x + 3 )$. (나) $g ( 0 ) = 1$ When $f ( 1 )$ is a natural number, what is the minimum value of $g ( 2 )$? [4 points]
(1) $\frac { 5 } { 13 }$
(2) $\frac { 5 } { 14 }$
(3) $\frac { 1 } { 3 }$
(4) $\frac { 5 } { 16 }$
(5) $\frac { 5 } { 17 }$
csat-suneung 2020 Q4 3 marks Evaluate Composition from Diagram or Mapping View
The figure shows two functions $f : X \rightarrow X , g : X \rightarrow X$. What is the value of $( g \circ f ) ( 1 )$? [3 points]
(1) 1
(2) 3
(3) 5
(4) 7
(5) 9
csat-suneung 2020 Q7 3 marks Find or Apply an Inverse Function Formula View
For the function $f ( x ) = \frac { k } { x - 3 } + 1$, when $f ^ { - 1 } ( 7 ) = 4$, what is the value of the constant $k$? (Note: $k \neq 0$) [3 points]
(1) 2
(2) 4
(3) 6
(4) 8
(5) 10
csat-suneung 2020 Q25 4 marks Derivative of an Inverse Function View
For the function $f ( x ) = \left( x ^ { 2 } + 2 \right) e ^ { - x }$, the function $g ( x )$ is differentiable and satisfies
$$g \left( \frac { x + 8 } { 10 } \right) = f ^ { - 1 } ( x ) , \quad g ( 1 ) = 0$$
Find the value of $\left| g ^ { \prime } ( 1 ) \right|$. [4 points]
Consider the function $$f ( x ) = \begin{cases} - 3 x + a & ( x \leq 1 ) \\ \frac { x + b } { \sqrt { x + 3 } - 2 } & ( x > 1 ) \end{cases}$$ If $f ( x )$ is continuous on the entire set of real numbers, find the value of $a + b$. (Here, $a$ and $b$ are constants.) [4 points]
csat-suneung 2024 Q4 3 marks Finding Parameters for Continuity View
Consider the function $$f(x) = \begin{cases} 3x - a & (x < 2) \\ x^2 + a & (x \geq 2) \end{cases}$$ If $f$ is continuous on the set of all real numbers, find the value of the constant $a$. [3 points]
(1) 1
(2) 2
(3) 3
(4) 4
(5) 5
The function $$f(x) = \left\{ \begin{array}{cc} 5x + a & (x < -2) \\ x^{2} - a & (x \geq -2) \end{array} \right.$$ is continuous on the set of all real numbers. What is the value of the constant $a$? [3 points]
(1) 6
(2) 7
(3) 8
(4) 9
(5) 10
csat-suneung 2026 Q3 3 marks Finding Parameters for Continuity View
The function $$f ( x ) = \begin{cases} 3 x - 2 & ( x < 1 ) \\ x ^ { 2 } - 3 x + a & ( x \geq 1 ) \end{cases}$$ is continuous on the set of all real numbers. What is the value of the constant $a$? [3 points]
(1) 1
(2) 2
(3) 3
(4) 4
(5) 5
19. (Total Score: 14 points) Subquestion 1 is worth 6 points, Subquestion 2 is worth 8 points.
Let the domain of function $f ( x ) = \sqrt { 2 - \frac { x + 3 } { x + 1 } }$ be $A$, and the domain of $g ( x ) = \lg [ ( x - a - 1 ) ( 2 a - x ) ]$ (where $a < 1$) be $B$.
(1) Find $A$;
(2) If $B \subseteq A$, find the range of real number $a$.
8. For any positive number $a$ not equal to 1, the graph of the inverse function of $f ( x ) = \log _ { a } ( x + 3 )$ always passes through point $P$. Then the coordinates of point $P$ are $\_\_\_\_$ $(0, -2)$
Analysis: The graph of $f ( x ) = \log _ { a } ( x + 3 )$ passes through the fixed point $( - 2,0 )$, so the graph of its inverse function passes through the fixed point $( 0 , - 2 )$
9. The coordinates of the intersection point of the graph of the inverse function of $f ( x ) = \log _ { 3 } ( x + 3 )$ with the $y$-axis are $\_\_\_\_$.
3. If the inverse function of $f(x) = 2x + 1$ is $f^{-1}(x)$, then $f^{-1}(-2) =$ $\_\_\_\_$
gaokao 2015 Q1 Set Operations View
1. Let $M = \left\{ x \mid x ^ { 2 } = x \right\} , N = \{ x \mid \lg x \leq 0 \}$, then $M \bigcup N =$
A. $[ 0,1 ]$
B. $( 0,1 ]$
C. $[ 0,1 )$
D. $( - \infty , 1 ]$
gaokao 2015 Q3 5 marks Solve a Logarithmic Inequality View
The domain of the function $f ( \mathrm { x } ) = \log _ { 2 } \left( \mathrm { x } ^ { 2 } + 2 \mathrm { x } - 3 \right)$ is
(A) $[ - 3,1 ]$
(B) $( - 3,1 )$
(C) $( - \infty , - 3 ] \cup [ 1 , + \infty )$
(D) $( - \infty , - 3 ) \cup ( 1 , + \infty )$
6. The domain of the function $f ( x ) = \sqrt { 4 - | x | } + \lg \frac { x ^ { 2 } - 5 x + 6 } { x - 3 }$ is
A. $ ( 2,3 )$
B. $ ( 2,4 ]$
C. $ ( 2,3 ) \cup ( 3,4 ]$
D. $ ( - 1,3 ) \cup ( 3,6 ]$
7. There exists a function $f ( x )$ satisfying, for all $x \in \mathbb{R}$,
A. $f ( \sin 2 x ) = \sin x$
B. $f ( \sin 2 x ) = x ^ { 2 } + x$
C. $f \left( x ^ { 2 } + 1 \right) = | x + 1 |$
D. $f \left( x ^ { 2 } + 2 x \right) = | x + 1 |$