book Maths Puzzle Numerical Ability

I have a trig. problem that I hope someone can help me with.
Sec2Csc2 - Sec2 - Csc2 + 1

Read Solution (Total 0)

book Other Question

When solving a rational equation, why is it OK to remove the denominator by multiplying both sides by the LCD and why can you not do the same operation when simplifying a rational what is the answer to this??? 5(9+3)-3(4)