Is #f(x)=tanx# concave or convex at #x=0#? Calculus Graphing with the Second Derivative Analyzing Concavity of a Function 1 Answer Jim H Nov 21, 2015 It is neither. Explanation: #f''(x) = 2sec^2xtanx# which is negative for #x < 0# and positive for #x > 0#. The concavity of the graph changes at #x=0#, so #(0,0)# is an inflection point.. Answer link Related questions How do you determine the concavity of a quadratic function? How do you find the concavity of a rational function? What is the concavity of a linear function? What x values is the function concave down if #f(x) = 15x^(2/3) + 5x#? How do you know concavity inflection points, and local min/max for #f(x) = 2x^3 + 3x^2 - 432x#? How do you determine the concavity for #f(x) = x^4 − 32x^2 + 6#? How do you find the intervals on which the graph of #f(x)=5sqrtx-1# is concave up or is concave... How do you determine where the given function #f(x) = (x+3)^(2/3) - 6# is concave up and where... How do you determine the intervals on which function is concave up/down & find points of... On what intervals the following equation is concave up, concave down and where it's inflection... See all questions in Analyzing Concavity of a Function Impact of this question 2355 views around the world You can reuse this answer Creative Commons License