Question

(1-sin d)(1+sin d) ————————— cos d

Answer 1

((1-sind)(1+sind))\cosd=(1-sin²d))\cosd=cos²d\cosd=cosd

Answer 2

The expression you provided can be simplified as follows:

(1 - sin(d))(1 + sin(d)) / cos(d)

First, notice that (1 - sin(d))(1 + sin(d)) is the difference of squares, which simplifies to:

(1 - sin^2(d))

Now, you can use the trigonometric identity sin^2(d) + cos^2(d) = 1 to rewrite this expression:

(1 - sin^2(d)) = cos^2(d)

So, the expression simplifies to:

cos^2(d) / cos(d)

Now, divide cos^2(d) by cos(d):

cos^2(d) / cos(d) = cos(d)

So, the simplified expression is cos(d).