AB > 0, then minimum value of sec A + sec B is equal to   



Correct option is





Now sec A is a decreasing function and tan A is a decreasing. 

So if A < B






(to check whether it is min or max) check value at A= 0, ).



Determine the absolute extrema for the following function and interval.

             g(t) = 2t3 + 3t2 – 12t + 4    on    [– 4, 2]  


Find the local maximum and local minimum values of the function y = xx.


A window is in the form of a rectangle surmounted by a semi-circle. The total area of window is fixed. What should be the ratio of the areas of the semi-circular part and the rectangular part so that the total perimeter is minimum?   


A box of constant volume C is to be twice as long as it is wide. The cost per unit area of the material on the top and four sides is three times the cost for bottom. What are the most economical dimensions of the box?  


Find the maximum surface area of a cylinder that can be inscribed in a given sphere of radius R 


Find the semi-vertical angle of the cone of maximum curved surface area that can be inscribed in a given sphere of radius R.


Find the point on the curve y = x2 which is closest to the point A(0, a).  


Find the shortest distance between the line y – x = 1 and the curve x = y2.


Find the vertical angle of right circular some of minimum curved surface that circumscribes in a given sphere.