MCQ
If ${\cos ^{ - 1}}\frac{3}{5} - {\sin ^{ - 1}}\frac{4}{5} = {\cos ^{ - 1}}x,$ then  $ x=$
  • A
    $0$
  • $1$
  • C
    $-1$
  • D
    $2$

Answer

Correct option: B.
$1$
b
(b) ${\cos ^{ - 1}}\frac{3}{5} - {\sin ^{ - 1}}\frac{4}{5} = {\cos ^{ - 1}}x$

$ \Rightarrow {\cos ^{ - 1}}\frac{3}{5} - {\cos ^{ - 1}}\sqrt {1 - \frac{{16}}{{25}}} = {\cos ^{ - 1}}x$

$ \Rightarrow {\cos ^{ - 1}}\frac{3}{5} - {\cos ^{ - 1}}\frac{3}{5} = {\cos ^{ - 1}}x$

$ \Rightarrow {\cos ^{ - 1}}x = 0 \Rightarrow x = 1$.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Let $R$ be a relation from $A = \{2,3,4,5\}$ to $B = \{3,6,7,10\}$ defined by $R = \{(a,b) |$ $a$ divides $b, a \in A, b \in B\}$, then number of elements in $R^{-1}$ will be-
The direction cosines of the straight linegiven by the planes x = 0 and z = 0 are:
  1. 1, 0, 0
  2. 0, 0, 1
  3. 1, 1, 0
  4. 0, 1, 0
Let $f$ and $g$ be twice differentiable even functions on $(-2,2)$ such that $f\left(\frac{1}{4}\right)=0, f\left(\frac{1}{2}\right)=0, f(1)=1$ and $g\left(\frac{3}{4}\right)=0, g(1)=2$ Then, the minimum number of solutions of $f(x) g^{\prime \prime}(x)+f^{\prime}(x) g^{\prime}(x)=0$ in $(-2,2)$ is equal to
Let $f\left( x \right) = {\sin ^4}\,x + {\cos ^4}\,x$. Then $f$ is an increasing function in the interval 
Choose the correct answer from the given four options.

If $\text{P}(\text{A})=\frac{2}{5},\text{P}(\text{B})=\frac{3}{5}$ and $\text{P}(\text{A}\cap\text{B})=\frac{1}{5},$ then $\text{P}\Big(\frac{\text{A}'}{\text{B}'}\Big)\cdot\text{P}\Big(\frac{\text{B}'}{\text{A}'}\Big)$ is equas:

  1. $\frac{5}{6}$

  2. $\frac{5}{7}$

  3. $\frac{25}{42}$

  4. $1$

$f: A \rightarrow B$ and $g: B \rightarrow C$ be two invertible functions then $(g \circ f)^{-1}=$ _________.
The principal value of $\cos ^{-1}\left(\frac{1}{2}\right)+\sin ^{-1}\left(\frac{-1}{\sqrt{2}}\right)$
If $4\cos^{-1}\text{x}+\sin^{-1}\text{x}=\pi,$ then the value of x is:
  1. $\frac{3}{2}$
  2. $\frac{1}{\sqrt2}$
  3. $\frac{\sqrt3}{2}$
  4. $\frac{2}{\sqrt3}$
If the function $f(x) = \left[ {\frac{{{{(x - 2)}^3}}}{a}} \right]\,\sin \,(x - 2)\, + a\cos (x - 2)\,$ is continious in $[4, 6],$ then the value of $a$ is $([.]$ denotes the greatest integer function)
Integrating factor of differential equation $\frac{d y}{d x}+y \tan x-\sec x=0$ is