To simplify this expression, we can use the difference of squares identity:
(1-sin d)(1+sin d) = 1^2 - (sin d)^2 = 1 - sin^2 d = cos^2 d
Therefore, the expression simplifies to:
cos^2 d / cos d = cos d
To simplify this expression, we can use the difference of squares identity:
(1-sin d)(1+sin d) = 1^2 - (sin d)^2 = 1 - sin^2 d = cos^2 d
Therefore, the expression simplifies to:
cos^2 d / cos d = cos d