Answer:
Please check explanations
Step-by-step explanation:
Using the difference of two squares, the lowest common multiple becomes;
1-sin^2 a
Thus, we have that;
cos a (1-sin a) + cos a (1 + sin a) /1 - sin^2 a
1 - sin^2 a = cos^2 a
That means;
{cos a - cos a sin a + cos a + cos a sin a}/ cos^2 a
= 2cos a / cos^2 a
= 2/cos a
but 1/cos a = sec a
Thus;
2/ cos a = 2 sec a
