Question

Q.19 If 1 / (b + c) 1 / (c + a) 1 / (a + b) are in AP then (a) a, b, c are in AP (b) a ^ 2, b ^ 2, c ^ 2 are in AP (c) l / a 1/b. 1 / c are in AP (d) None of these​

Answer 1

Step-by-step explanation:

a,b,c in AP

2b= a+c _________ (1)

To prove

b

+

c

1

.

c

+

a

1

,

a

+

b

1

in AP

c

+

a

1

−

b

+

c

1

=

a

+

b

1

−

c

+

a

1

b

+

c

b

−

a

=

a

+

b

c

−

b

⇒(

b

−

a

)(

b

−

a

)=(

c

−

b

)(

c

−

b

)

To prove b-a = c-b

2b=a+c which is true.