Home
Class 11
MATHS
In Delta ABC Prove that cos A + co...

In ` Delta ABC ` Prove that
` cos A + cos B+ cos C =1 + ( r ) / ( R ) `

Text Solution

Verified by Experts

The correct Answer is:
`1+ ( r)/( R ) = R.H.S.`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • PROPERTIES OF TRIANGLES

    VIKRAM PUBLICATION ( ANDHRA PUBLICATION)|Exercise TEXTUAL EXERCISES ( EXERCISE - 10(b) ) II.|6 Videos

  • PRODUCT OF VECTORS

    VIKRAM PUBLICATION ( ANDHRA PUBLICATION)|Exercise SOLVED PROBLEMS|46 Videos

  • STRAIGHT LINE

    VIKRAM PUBLICATION ( ANDHRA PUBLICATION)|Exercise TEXTUAL EXERCISES (EXERCISE-3(e)) |32 Videos

Similar Questions

Explore conceptually related problems

Prove that a cos A + b cos B + c cos C = 4 R sin A sin B sin C .

In Delta ABC , prove that r+ r_1 + r_2 - r_3 = 4R cos C .

Knowledge Check

  • In Delta ABC if 5r = 2R then cos A + cos B + cos C =

    A
    ` ( 7)/(5) `
    B
    ` (3)/(4)`
    C
    ` ( 2)/(5) `
    D
    ` ( 4)/( 7) `

  • In Delta ABC, if 4r=3R then cos A+ cos B+ cos C=

    A
    `1//4`
    B
    `3//4`
    C
    `5//4`
    D
    `7//4`

  • In Delta ABC , if cos A + 2 cos B + cos C = 2 then a,b,c = in

    A
    A.P.
    B
    H.P.
    C
    G.P.
    D
    A.G.P

    • Similar Questions

    Explore conceptually related problems

    In Delta ABC , express ( a cos A + b cos B + c cos C)/( a + b + c) in terms or R and r.

    In Delta ABC if a =2, b= 3, c = 4 then cos A + cos B + cos C =

    In Delta ABC , a( b cos C - c cos B) =

    In a triangle ABC, cos A + cos B + cos C

    If a triangle ABC, cos A + cos B + cos C

    Home
    Profile