+0

# trig

0
111
1

Simplify $$\left( \dfrac1{\cos a} - \dfrac{\sin a}{\cos a} \right) \left( \dfrac1{\cos a} + \dfrac{\sin a}{\cos a} \right)$$

Jun 24, 2020

#1
+2175
0

I think this will be the same as this rule:

(a+b)(a-b)=a^2-b^2

So, our answer will be

1/cos a minus sin a/cos a

Jun 24, 2020