Question

Which of the following equations are identities? More than one....
A. tan^2 x = sec^2 x - 1
B. sin^2 x - cos^2 x = 1
C. sin^2 = 1 - cos^2 x
D. cot^2 x + csc^2 x = 1

Answer 1

you should know sin^2(x) + cos^2(x) = 1
divide both sides by cos^2(x) and you get
sin^2(x)/cos^2(x) + 1 = 1/cos^2(x)
this becomes
tan^2(x) + 1 = sec^2(x)
so tan^2(x) = sec^2(x) -1

Answer 2

sin^2(x) + cos^2(x) = 1
sin^2(x) = 1 - cos^2(x)

Answer 3

.....?

Answer 4

...basically a and c are identtiies

Answer 5

just those? ..for sure?

Answer 6

yea]