Question

The curve \( ax^3+bx^2+cx+d \) has a point of minima at \( x=1 \), then

• A. \(3a+b<0\)
• B. \(3a+b>0\)
• C. \(3a+b=0\)
• D. \(a+3b>0\)

Hint:

For minima, use the second derivative test: if \(f'(x)=0\) and \(f''(x)>0\), then the point is a local minimum.

Answer 1

The Correct Option is B