Question

answer this 7th question please know spamming​

Answer 1

f(a) = f(-a)

that means between a and -a there should be point where f'(x)= 0

f(x) = ax^2 + bx + c

f'(x) = 2ax + b

f'(a) = 2a^2 + b

f'(-a) = -2a^2 + b

f(a) = f(-a)

a^3 + ba + c= a^3 - ba + c

2ba = 0

b= 0 , a can't be 0

f'(a) = 2a^2

f'(-a) = -2a^2

So f'(x) becomes 2ax

a,b,c in AP

f'(x) proportional to x

so if a,b,c in ap

then f'(a),f'(b),f'(c) is also in AP

its 4) AP

Answer 2

Answer:

I hope it would help you.

thank you.