y=sec^2(3.14/2-x),x=-3.14/2 then find equation of tangent line to the graph

Question

3.14 is actually pie

Answer 1

y=sec²(π/2-x), dy/dx=2sec²(π/2-x)tan(π/2-x).

When x=-π/2, dy/dx=0 (horizontal line), and y=sec²(π)=(-1)²=1.

Since the tangent is at (-π/2,1) and the tangent line is horizontal it must be y=1.