Question

question no. 14.........

Answer 1

given the function is differentiable.
so it should be continuous function. then the function value should be same at 1.
then
x^3+2x^2
${x}^{3} + 2 {x}^{2} = - {x}^{3} + 2 {x}^{2} + ax$
substitute x=1
by solving you will get a=2