Home
Class 11
MATHS
Prove that:(cos4x+cos3x+cos2x)/(sin4x+si...

Prove that:`(cos4x+cos3x+cos2x)/(sin4x+sin3x+sin2x)=cot3x`

Text Solution

Verified by Experts

`frac{cos 4x+cos3x+cos2x}{sin4x+sin3x+sin2x}=frac{cos4x+cos2x+cos3x}{sin4x+sin2x+sin3x}`
`=frac{(cos4x+cos2x)+cos3x}{(sin4x+sin2x)+sin3x}`
`= (2cos3xcosx+cos3x)/(2sin3xcosx+sin3x)` ​
`= (cos3x[2cosx+1]) / (sin3x[2cosx+1])` ...
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • TRIGONOMETRIC FUNCTIONS

    NCERT|Exercise MISCELLANEOUS EXERCISE|10 Videos
  • TRIGONOMETRIC FUNCTIONS

    NCERT|Exercise EXERCISE 3.1|7 Videos
  • TRIGONOMETRIC FUNCTIONS

    NCERT|Exercise EXERCISE 3.4|9 Videos
  • STRAIGHT LINES

    NCERT|Exercise EXERCISE 10.5|2 Videos

Similar Questions

Explore conceptually related problems

cos3x-cos2x=sin3x

Prove that: ,(cos9x-cos5x)/(sin17x-sin3x)=-(sin2x)/(cos10x)

Knowledge Check

  • The expression ("cos" 4x+"cos" 3x+"cos"2x)/("sin" 4x+"sin" 3x+ "sin" 2x) is equal to

    A
    `-cot 3x`
    B
    cot 3x
    C
    cot 2x
    D
    `-cat 2x`
  • Similar Questions

    Explore conceptually related problems

    Prove that :(cos9x-cos5x)/(sin17x-sin3x)=(-sin2x)/(cos10x)

    Prove that: cos^(2)2x-cos^(2)6x=sin4x sin8x

    Solve int(cos4x-cos2x)/(sin4x-sin2x)dx

    Prove that (cos3x)/(sin2x sin4x)+(cos5x)/(sin4x sin6x)+(cos7x)/(sin6x sin8x)+(cos9x)/(sin8x sin10x)=(1)/(2)(cos ecx)[cos ec2x-cos ec10x]

    show that (1)/(2sin x)(csc2x-cos ec4x)=(cos3x)/(sin2x sin4x) and hence prove that (cos3x)/(sin2x sin4x)+(cos5x)/(sin4x sin6x)+(cos7x)/(sin6x sin8x)+......+ terms =(1)/(2sin x)[cos ec2x-cos ec(2n+2)x]

    Evaluate: int(cos4x-cos2x)/(sin4x-sin2x)dx

    prove that cos x cos2x cos4x cos8x=(sin16x)/(16sin x)