Home
Class 11
MATHS
In DeltaABC, prove that: (b+c)cos(B+C)...

In `DeltaABC`, prove that:
`(b+c)cos(B+C)/(2)=acos(B-C)/(2)`

Text Solution

AI Generated Solution

To prove that in triangle ABC, \((b+c) \cos\left(\frac{B+C}{2}\right) = a \cos\left(\frac{B-C}{2}\right)\), we will follow these steps: ### Step 1: Start with the Left-Hand Side (LHS) We begin with the left-hand side of the equation: \[ LHS = (b+c) \cos\left(\frac{B+C}{2}\right) \] ...
Promotional Banner

Topper's Solved these Questions

  • TRIGNOMETRIC FUNCTIONS

    NAGEEN PRAKASHAN ENGLISH|Exercise EXERCISES 3A|12 Videos

  • TRIGNOMETRIC FUNCTIONS

    NAGEEN PRAKASHAN ENGLISH|Exercise EXERCISES 3B|24 Videos

  • STRAIGHT LINES

    NAGEEN PRAKASHAN ENGLISH|Exercise Exercise|207 Videos

Similar Questions

Explore conceptually related problems

For any triangle ABC, prove that (b+c)cos((B+C)/2)=acos((B-C)/2)

In DeltaABC , prove that: (a-b)/c=(sin(A-B)/(2))/(cosC/2)

In DeltaABC , prove that: (bcos^(2)C)/2+(c cos^(2)B)/2=s

In DeltaABC , prove that: b(cosA-cosC)=2(c-a)cos^(2)B/2

In DeltaABC , prove that: (b-c)/acos^(2)A/2+(c-a)/(b)cos^(2)B/2+(a-b)/(c ).cos^(2)C/2=0

In DeltaABC , prove that: (1+cosA.cos(B-C))/(1+cosC.cos(A-B))=(b^(2)+c^(2))/(a^(2)+b^(2))

In any DeltaABC , prove that : If b+c = 2a cos ((B-C)/2) , then prove that A=60^0 .

In DeltaABC , prove that: a(cosC-cosB)=2(b-c)cos^(2)A/2

In any DeltaABC , prove that : (cos^2(A/2))/a + (cos^2(B/2))/b + (cos^2(C/2))/c = s^2/(abc)

In any DeltaABC , prove that (a+b-c) cot (B/2) = (a-b+c) cot (C/2)