मराठी

If T N = Sin N X + Cos N X , Prove that 6 T 10 − 15 T 8 + 10 T 6 − 1 = 0 - Mathematics

Advertisements
Advertisements

प्रश्न

If \[T_n = \sin^n x + \cos^n x\], prove that \[6 T_{10} - 15 T_8 + 10 T_6 - 1 = 0\]

उत्तर

LHS = \[6 T_{10} - 15 T_8 + 10 T_6 - 1\]
\[=6\left( \sin^{10} x + \cos^{10} x \right) - 15\left( \sin^8 x + \cos^8 x \right) + 10\left( \sin^6 x + \cos^6 x \right) - 1\]
`=6(sin^2x+cos^2x)(sin^8x+cos^8x-sin^2xcos^2x)-15(sin^8x+cos^8x)+10(sin^6x+cos^6x)-1`
`=6(sin^8x+cos^8x-sin^2xcos^2x)-15(sin^8x+cos^8x)+10(sin^6x+cos^6x)-1`
`=6sin^8x+6cos^8x-6sin^2xcos^2x-15sin^8x-15cos^8x+10(sin^6x+cos^6x)-1`

`=-6sin^2xcos^2x-9sin^8x-9cos^8x+10(sin^6x+cos^6x)-1`
`=-6sin^2xcos^2x-9(sin^8x+cos^8x)+10(sin^6x+cos^6x)-1`
`=-6sin^2xcos^2x-9(sin^2x+cos^2x)(sin^6x+cos^6x-sin^2xcos^2x)+10(sin^6x+cos^6x)-1`
`=-6sin^2xcos^2x-9(sin^6x+cos^6x-sin^2xcos^2x)+10(sin^6x+cos^6x)-1`
`=-6sin^2xcos^2x-9sin^6x-9cos^6x+9sin^2xcos^2x+10sin^6x+10cos^6x-1`
`=3sin^2xcos^2x+sin^6x+cos^6x-1`
`=3sin^2xcos^2x+(sin^2x+cos^2x)(sin^4x+cos^4x-sin^2xcos^2x)-1`
`=3sin^2xcos^2x+sin^4x+cos^4x-sin^2xcos^2x-1`

`=(sin^2x)^2+2sin^2xcos^2x+(cos^2x)^2-1`
`=(sin^2x+cos^2x)^2-1`
=12-1
=0
=RHS

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 5: Trigonometric Functions - Exercise 5.1 [पृष्ठ १९]

APPEARS IN

आरडी शर्मा Mathematics [English] Class 11
पाठ 5 Trigonometric Functions
Exercise 5.1 | Q 26.3 | पृष्ठ १९

व्हिडिओ ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्‍न

Find the principal and general solutions of the equation sec x = 2


Find the principal and general solutions of the equation  `cot x = -sqrt3`


Find the general solution for each of the following equations sec2 2x = 1– tan 2x


If \[\sin x = \frac{a^2 - b^2}{a^2 + b^2}\], then the values of tan x, sec x and cosec x


If \[\tan x = \frac{b}{a}\] , then find the values of \[\sqrt{\frac{a + b}{a - b}} + \sqrt{\frac{a - b}{a + b}}\].


Prove the:
\[ \sqrt{\frac{1 - \sin x}{1 + \sin x}} + \sqrt{\frac{1 + \sin x}{1 - \sin x}} = - \frac{2}{\cos x},\text{ where }\frac{\pi}{2} < x < \pi\]


Prove that

\[\frac{\tan (90^\circ - x) \sec(180^\circ - x) \sin( - x)}{\sin(180^\circ + x) \cot(360^\circ - x) cosec(90^\circ - x)} = 1\]

 


In a ∆ABC, prove that:
cos (A + B) + cos C = 0


Prove that:
\[\tan 4\pi - \cos\frac{3\pi}{2} - \sin\frac{5\pi}{6}\cos\frac{2\pi}{3} = \frac{1}{4}\]


Prove that:

\[\tan\frac{5\pi}{4}\cot\frac{9\pi}{4} + \tan\frac{17\pi}{4}\cot\frac{15\pi}{4} = 0\]

 


sin6 A + cos6 A + 3 sin2 A cos2 A =


The value of sin25° + sin210° + sin215° + ... + sin285° + sin290° is


The value of \[\cos1^\circ \cos2^\circ \cos3^\circ . . . \cos179^\circ\] is

 

Which of the following is correct?


Find the general solution of the following equation:

\[\sin x = \frac{1}{2}\]

Find the general solution of the following equation:

\[\sec x = \sqrt{2}\]

Find the general solution of the following equation:

\[\sin 2x = \cos 3x\]

Find the general solution of the following equation:

\[\tan x + \cot 2x = 0\]

Find the general solution of the following equation:

\[\tan mx + \cot nx = 0\]

Find the general solution of the following equation:

\[\sin 2x + \cos x = 0\]

Solve the following equation:
\[\sin^2 x - \cos x = \frac{1}{4}\]


Solve the following equation:

\[\tan^2 x + \left( 1 - \sqrt{3} \right) \tan x - \sqrt{3} = 0\]

Solve the following equation:

\[\tan x + \tan 2x + \tan 3x = 0\]

Solve the following equation:

\[\sin x + \cos x = 1\]

Solve the following equation:
4sinx cosx + 2 sin x + 2 cosx + 1 = 0 


Solve the following equation:
3tanx + cot x = 5 cosec x


Solve the following equation:
3 – 2 cos x – 4 sin x – cos 2x + sin 2x = 0


Write the values of x in [0, π] for which \[\sin 2x, \frac{1}{2}\]

 and cos 2x are in A.P.


Write the number of values of x in [0, 2π] that satisfy the equation \[\sin x - \cos x = \frac{1}{4}\].


If \[3\tan\left( x - 15^\circ \right) = \tan\left( x + 15^\circ \right)\] \[0 < x < 90^\circ\], find θ.


The general solution of the equation \[7 \cos^2 x + 3 \sin^2 x = 4\] is


The number of solution in [0, π/2] of the equation \[\cos 3x \tan 5x = \sin 7x\] is 


The general value of x satisfying the equation
\[\sqrt{3} \sin x + \cos x = \sqrt{3}\]


If \[e^{\sin x} - e^{- \sin x} - 4 = 0\], then x =


If \[\sqrt{3} \cos x + \sin x = \sqrt{2}\] , then general value of x is


The solution of the equation \[\cos^2 x + \sin x + 1 = 0\] lies in the interval


Solve the following equations:
`sin theta + sqrt(3) cos theta` = 1


Solve `sqrt(3)` cos θ + sin θ = `sqrt(2)`


Number of solutions of the equation tan x + sec x = 2 cosx lying in the interval [0, 2π] is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×