JEE Main2004MathematicsApplication of DerivativesActual
A function y=f(x) has a second order derivative f^ (x)=6(x-1) . If its graph passes through the point (2,1) and at that point the tangent to the graph is y=3 x-5 , then the function is
Options
- A(x-1)^2
- B(x-1)^3
- C(x+1)^3
- D(x+1)^2
Correct answer
B. (x-1)^3
Step-by-step solution
f^ (x)=6(x-1) f^ (x)=3(x-1)^2+c and f^ (2)=3 c=0 f(x)=(x-1)^3+k and f(2)=1 k=0 f(x)=(x-1)^3