हिंदी

The number of real solutions of the equation 1+cos2x=2cos-1(cosx) in [π2,π] is ______. - Mathematics

Advertisements
Advertisements

प्रश्न

The number of real solutions of the equation `sqrt(1 + cos 2x) = sqrt(2) cos^-1 (cos x)` in `[pi/2, pi]` is ______.

विकल्प

  • 0

  • 1

  • 2

  • Infinite

MCQ
रिक्त स्थान भरें
Advertisements

उत्तर

The number of real solutions of the equation `sqrt(1 + cos 2x) = sqrt(2) cos^-1 (cos x)` in `[pi/2, pi]` is 0.

Explanation:

We have `sqrt(1 + cos 2x) = sqrt(2) cos^-1 (cos x)` 

⇒ `sqrt(2 cos^2x) = sqrt(2)x`        ...`[because cos^-1 (cos x) = x]`

⇒ `sqrt(2) cos x = sqrt(2)x`

⇒ cos x = x

∴ There are no solution for given equation.

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 2: Inverse Trigonometric Functions - Exercise [पृष्ठ ३९]

APPEARS IN

एनसीईआरटी एक्झांप्लर Mathematics [English] Class 12
अध्याय 2 Inverse Trigonometric Functions
Exercise | Q 36 | पृष्ठ ३९

संबंधित प्रश्न

Prove that `2tan^(-1)(1/5)+sec^(-1)((5sqrt2)/7)+2tan^(-1)(1/8)=pi/4`


Solve for x : tan-1 (x - 1) + tan-1x + tan-1 (x + 1) = tan-1 3x


Write the following function in the simplest form:

`tan^(-1) ((3a^2 x - x^3)/(a^3 - 3ax^2)), a > 0; (-a)/sqrt3 < x < a/sqrt3`


Prove that:

`cot^(-1)  ((sqrt(1+sin x) + sqrt(1-sinx))/(sqrt(1+sin x) - sqrt(1- sinx))) = x/2, x in (0, pi/4)`


Prove that

\[2 \tan^{- 1} \left( \frac{1}{5} \right) + \sec^{- 1} \left( \frac{5\sqrt{2}}{7} \right) + 2 \tan^{- 1} \left( \frac{1}{8} \right) = \frac{\pi}{4}\] .

 

If cos-1 x + cos -1 y + cos -1 z = π , prove that x2 + y2 + z2 + 2xyz = 1.


Find the value, if it exists. If not, give the reason for non-existence

`sin^-1 (cos pi)`


Find the value of `cot[sin^-1  3/5 + sin^-1  4/5]`


Find the value of  `tan(sin^-1  3/5 + cot^-1  3/2)`


Prove that `tan^-1x + tan^-1y + tan^-1z = tan^-1[(x + y + z - xyz)/(1 - xy - yz - zx)]`


Solve: `sin^-1  5/x + sin^-1  12/x = pi/2`


Choose the correct alternative:

If |x| ≤ 1, then `2tan^-1x - sin^-1  (2x)/(1 + x^2)` is equal to


Choose the correct alternative:

If `sin^-1x + cot^-1 (1/2) = pi/2`, then x is equal to


Evaluate `tan^-1(sin((-pi)/2))`.


Evaluate: `tan^-1 sqrt(3) - sec^-1(-2)`.


Prove that cot–17 + cot–18 + cot–118 = cot–13


Show that `2tan^-1 {tan  alpha/2 * tan(pi/4 - beta/2)} = tan^-1  (sin alpha cos beta)/(cosalpha + sinbeta)`


Prove that `tan^-1 ((sqrt(1 + x^2) + sqrt(1 - x^2))/((1 + x^2) - sqrt(1 - x^2))) = pi/2 + 1/2 cos^-1x^2`


Show that `tan(1/2 sin^-1  3/4) = (4 - sqrt(7))/3` and justify why the other value `(4 + sqrt(7))/3` is ignored?


If `sin^-1 ((2"a")/(1 + "a"^2)) + cos^-1 ((1 - "a"^2)/(1 + "a"^2)) = tan^-1 ((2x)/(1 - x^2))`. where a, x ∈ ] 0, 1, then the value of x is ______.


The value of the expression `tan (1/2 cos^-1  2/sqrt(5))` is ______.


The maximum value of sinx + cosx is ____________.


The minimum value of sinx - cosx is ____________.


If `"sec" theta = "x" + 1/(4 "x"), "x" in "R, x" ne 0,`then the value of  `"sec" theta + "tan" theta` is ____________.


`"sin" {2  "cos"^-1 ((-3)/5)}` is equal to ____________.


The value of expression 2 `"sec"^-1  2 + "sin"^-1 (1/2)`


`"cot" ("cosec"^-1  5/3 + "tan"^-1  2/3) =` ____________.


`"cos" (2  "tan"^-1 1/7) - "sin" (4  "sin"^-1 1/3) =` ____________.


If x = a sec θ, y = b tan θ, then `("d"^2"y")/("dx"^2)` at θ = `π/6` is:


`"tan" (pi/4 + 1/2 "cos"^-1 "x") + "tan" (pi/4 - 1/2 "cos"^-1 "x") =` ____________.


The value of `"cos"^-1 ("cos" ((33pi)/5))` is ____________.


`"sin"^-1 (1/sqrt2)`


`"tan"^-1 (sqrt3)`


If `"sin"^-1 (1 - "x") - 2  "sin"^-1 ("x") = pi/2,` then x is equal to ____________.


What is the value of cos (sec–1x + cosec–1x), |x| ≥ 1


`sin^-1(1 - x) - 2sin^-1 x = pi/2`, tan 'x' is equal to


Find the value of `tan^-1 [2 cos (2 sin^-1  1/2)] + tan^-1 1`.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×