Zeros of a Min Function

Problem

Let f(x)=x3+ax+14f(x)=x^3+ax+\dfrac 14 and g(x)=−ln⁡xg(x)=-\ln x.

1. For what value of aa is the xx-axis tangent to the curve y=f(x)y=f(x)? 2. Writing min⁡{m,n}\min\{m,n\} for the smaller of m,nm,n, let h(x)=min⁡{f(x),g(x)}h(x)=\min\{f(x),g(x)\} for x>0x>0. Discuss the number of zeros of h(x)h(x).

Answer

Solution

Difficulty8/10
Topicsfunctions, Extrema, calculus, Monotonicity, Casework

Whiteboard

Your sketch is saved only in this browser. To share it, export your drawing as an image (whiteboard menu → Export as → PNG), then upload that image in the comments below.

Discussion

Ask questions, share alternate solutions, and use LaTeX freely.

0 comments
Log in to join the discussion.

No comments yet.