What mathematical operation changes 2 1/3 to 2 ?

Given (1+cosx)/(sinx) + (sinx)/(1+cosx) =4, find a numerical value of one trigonometric function of x. a. tanx=2 b. sinx=2 c. tanx=1/2 d. sinx=1/2

Choose the more precise measurement. 26.4 cm or 8.39 cm

What is the point of inflection for the function f(x)=2cos4x on the interval (0, pi/2)