Which of these are true or false?
1. sec^2(x) - 1 = tan^2(x)

2. sin2(x) / 2 = sin(x)

3. sin(x)+cos(x) / sin(x) = cos(x)

4. sin^2(x) = cos^2(x) -1

5. cot(x) + 1 = csc(x)

6. 2sin(x) = sin(x) + sin(x)

Question

Which of these are true or false?
1. sec^2(x) - 1 = tan^2(x)

2. sin2(x) / 2 = sin(x)

3. sin(x)+cos(x) / sin(x) = cos(x)

4. sin^2(x) = cos^2(x) -1

5. cot(x) + 1 = csc(x)

6. 2sin(x) = sin(x) + sin(x)

danjs · Answer

http://www.sosmath.com/trig/Trig5/trig5/trig5.html

anonymous · Answer

Fundamentally$$
\sin^2(x)+\cos^2(x)=1
$$Divide both sides by $\cos^2(x)$ and you get$$
\tan^2(x) + 1 = \sec^2(x)
$$Divide both sides by $\sin^2(x)$ and you get: $$
1+\cot^2(x) = \csc^2(x)
$$

anonymous · Answer

Then you can just check if the other formula seem to match up with these formula