Step 1: Define a helper polynomial:
\[ g(x) = f(x) - (x + 1) \]
Given: \( f(1) = 2, f(2) = 3, f(3) = 4, f(4) = 5 \Rightarrow g(1) = g(2) = g(3) = g(4) = 0 \)
So, \[ g(x) = A(x - 1)(x - 2)(x - 3)(x - 4) \quad \Rightarrow \quad f(x) = A(x - 1)(x - 2)(x - 3)(x - 4) + (x + 1) \]
Step 2: Use \( f(0) = 25 \) to find A:
\[ f(0) = A(-1)(-2)(-3)(-4) + (0 + 1) = 24A + 1 = 25 \Rightarrow A = 1 \]
Step 3: Compute \( f(5) \):
\[ f(5) = (5 - 1)(5 - 2)(5 - 3)(5 - 4) + (5 + 1) = 4 \cdot 3 \cdot 2 \cdot 1 + 6 = 24 + 6 = \boxed{30} \]
✅ Final Answer: \( \boxed{f(5) = 30} \)
Step 1: Let’s define the function:
\[ f(x) = (x - 1)^2 (x + 1)^3 \]
Step 2: Take derivative to find critical points
Use product rule:
Let \( u = (x - 1)^2 \), \( v = (x + 1)^3 \)
\[
f'(x) = u'v + uv' = 2(x - 1)(x + 1)^3 + (x - 1)^2 \cdot 3(x + 1)^2
\]
\[
f'(x) = (x - 1)(x + 1)^2 [2(x + 1) + 3(x - 1)]
\]
\[
f'(x) = (x - 1)(x + 1)^2 (5x - 1)
\]
Step 3: Find critical points
Set \( f'(x) = 0 \): \[ (x - 1)(x + 1)^2 (5x - 1) = 0 \Rightarrow x = 1,\ -1,\ \frac{1}{5} \]
Step 4: Evaluate \( f(x) \) at these points
\[ f\left(\frac{1}{5}\right) = \frac{16}{25} \cdot \frac{216}{125} = \frac{3456}{3125} \]
Step 5: Compare with given form:
It is given that maximum value is \( \frac{3456}{3125} = 2^p \cdot 3^q / 3125 \)
Factor 3456: \[ 3456 = 2^7 \cdot 3^3 \Rightarrow \text{So } p = 7, \quad q = 3 \]
✅ Final Answer: \( \boxed{(p, q) = (7,\ 3)} \)
Given: \( n(A)=6 \) and \( n(B)=3 \).
Formula: The number of onto (surjective) functions from a set of size \(m\) to a set of size \(n\) is \[ n! \, S(m,n) \] where \(S(m,n)\) is the Stirling number of the second kind (number of ways to partition \(m\) elements into \(n\) non-empty subsets).
We can also use the Inclusion–Exclusion Principle: \[ n! \, S(m,n) = \sum_{k=0}^{n} (-1)^k \binom{n}{k}(n-k)^m \] For \(m=6,\ n=3\): \[ N = 3^6 - 3\times 2^6 + 3\times 1^6 \]
Calculation: \[ 3^6 = 729,\quad 2^6 = 64 \] \[ N = 729 - 3(64) + 3(1) = 729 - 192 + 3 = 540. \]
Answer: The number of onto functions is \[ \boxed{540}. \]
Step 1: One-one (injective) function means no two elements map to the same output.
We choose 3 different elements from 5 and assign them to 3 inputs in order.
So, total one-one functions = $P(5,3) = 5 \times 4 \times 3 = 60$
✅ Final Answer: $\boxed{60}$
Given:
$$f\left(\frac{1 - x}{1 + x}\right) = x + 2$$
To Find: \( f(1) \)
Let \( \frac{1 - x}{1 + x} = 1 \Rightarrow x = 0 \)
Then, \( f(1) = f\left(\frac{1 - 0}{1 + 0}\right) = 0 + 2 = 2 \)
Answer: $$\boxed{2}$$
Given:
\[ f(x) = \cos\left([\pi^2]x\right) + \cos\left([-\pi^2]x\right) \]
Find: \[ f\left(\frac{\pi}{2}\right) \]
\[ \pi^2 \approx 9.8696 \Rightarrow [\pi^2] = 9,\quad [-\pi^2] = -10 \]
\[ f\left(\frac{\pi}{2}\right) = \cos\left(9 \cdot \frac{\pi}{2}\right) + \cos\left(-10 \cdot \frac{\pi}{2}\right) = \cos\left(\frac{9\pi}{2}\right) + \cos(-5\pi) \]
\[ \cos\left(\frac{9\pi}{2}\right) = 0,\quad \cos(-5\pi) = -1 \]
\[ \boxed{-1} \]
Even elements in the domain are $2$ and $4$.
Even elements in the codomain are $2,4,6,8$.
The two even elements of the domain must be mapped to even elements of the codomain injectively.
Number of ways:
${}^4P_2=4\times 3=12$
Now, $2$ elements of the codomain are already used, so $6$ elements are left.
The odd elements of the domain are $1$ and $3$.
They can be mapped injectively to the remaining $6$ elements.
Number of ways:
${}^6P_2=6\times 5=30$
So,
$n=12\times 30=360$
Now,
$360=2^3\times 3^2\times 5^1$
So,
$a=3,\ b=2,\ c=1$
Therefore,
$a+b+c=3+2+1=6$
Since
$R\subset \mathbb{N}\times \mathbb{N}$,
the relation $R$ can have at most countably infinite elements.
Now, suppose for some $a\in \mathbb{N}$, the set $R_a$ is infinite.
Since $R_a\subseteq \mathbb{N}$, it is countably infinite.
Also, for every element $b\in R_a$, the ordered pair $(a,b)$ belongs to $R$.
So, $R$ is also infinite. Since $R\subset \mathbb{N}\times \mathbb{N}$, $R$ is countably infinite.
Therefore, both $R_a$ and $R$ have the same cardinality.
| { | $1$ | if | $|x|\le 1$ |
| $0$ | if | $|x|>1$ |
| { | $2-x^2$ | if | $|x|\le 2$ |
| $2$ | if | $|x|>2$ |
Given,
$h(x)=f[g(x)]$
Now, $f(t)=1$ when
$|t|\le 1$
So, $h(x)=1$ when
$|g(x)|\le 1$
For $|x|\le 2$,
$g(x)=2-x^2$
So,
$|2-x^2|\le 1$
This gives
$-1\le 2-x^2\le 1$
Subtract $2$ from all sides:
$-3\le -x^2\le -1$
Multiplying by $-1$ reverses the inequalities:
$1\le x^2\le 3$
So,
$1\le |x|\le \sqrt{3}$
For $|x|>2$,
$g(x)=2$
So,
$|g(x)|=2>1$
Hence, this case is not valid.
Therefore, the required interval is
$1\le |x|\le \sqrt{3}$
Let $f:[0,\infty)\to \mathbb{R}$ be a function defined by
$f(x)=\frac{3x^2+4x+1}{x^2+3x+2}$
Then the value of $(f^{-1})'(2)$ is equal to:
We know that
$(f^{-1})'(y)=\frac{1}{f'(x)}$, where $f(x)=y$
Here, we need $(f^{-1})'(2)$.
So first find $x$ such that
$f(x)=2$
$\frac{3x^2+4x+1}{x^2+3x+2}=2$
$3x^2+4x+1=2x^2+6x+4$
$x^2-2x-3=0$
$(x-3)(x+1)=0$
Since domain is $[0,\infty)$,
$x=3$
Now,
$f(x)=\frac{3x^2+4x+1}{x^2+3x+2}$
Let
$N=3x^2+4x+1$
and
$D=x^2+3x+2$
Then,
$f'(x)=\frac{N'D-ND'}{D^2}$
Now at $x=3$,
$N=3(3)^2+4(3)+1=40$
$D=(3)^2+3(3)+2=20$
$N'=6x+4$
So,
$N'=22$
$D'=2x+3$
So,
$D'=9$
Therefore,
$f'(3)=\frac{22\cdot 20-40\cdot 9}{20^2}$
$f'(3)=\frac{440-360}{400}$
$f'(3)=\frac{80}{400}$
$f'(3)=\frac{1}{5}$
Hence,
$(f^{-1})'(2)=\frac{1}{f'(3)}$
$=5$
Online Test Series,
Information About Examination,
Syllabus, Notification
and More.
Online Test Series,
Information About Examination,
Syllabus, Notification
and More.
Commented Dec 16 , 2021
0 Upvote 0 Downvote Reply
Your reply to this comment :