differentiation

hey the ans is i think (c)

its is quest from arihant objectives....

take y = x³ and then find dy/dx further find d²y/dx²

then put in the 3 options to check which 1 of them satisfies.....

THIS IS THE SHORTEST TRICK 4 ENGG EXAMS....

I DON'T KNOW THE EXACT METHOD OF SOLVING SUCH PROBLEMS

can anyone tell me the exact method fr solving this problem