Maths-
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Easy

Question

If fraction numerator b over denominator c plus a end fraction plus fraction numerator c over denominator a plus b end fraction equals 1then

  1. A equals 60 to the power of ring operator
  2. B equals 60 to the power of ring operator
  3. C equals 60 to the power of ring operator
  4. A equals 90 to the power of ring operator

Hint:

To find the value of angle A we will solve the equation using the cosine formula .

The correct answer is: A equals 60 to the power of ring operator


    In triangleABC,
    fraction numerator c over denominator a plus b end fraction plus fraction numerator b over denominator c plus a end fraction equals 1
rightwards double arrow fraction numerator c left parenthesis c plus a right parenthesis plus b left parenthesis a plus b right parenthesis over denominator left parenthesis a plus b right parenthesis left parenthesis c plus a right parenthesis end fraction equals 1
rightwards double arrow c squared plus a c plus a b plus b squared equals left parenthesis a plus b right parenthesis left parenthesis a plus c right parenthesis
rightwards double arrow c squared plus a c plus a b plus b squared equals a squared plus a c plus a b plus b c
rightwards double arrow c squared plus b squared minus a squared equals b c
rightwards double arrow 2. b c. cos A equals b c space space space open square brackets b y space cos i n e space f o r m u l a close square brackets
rightwards double arrow 2 cos A equals 1
rightwards double arrow cos A equals 1 half
rightwards double arrow A equals 60 degree

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