Question

Which of the following are identities?

Answer 1

\[\sin^2\theta+\cos ^2 \theta=1\]
\[\sin \theta+\cos \theta=1\]
\[\sec \theta+\csc \theta=1\]
\[\tan^2\theta=\frac{ 1 }{ \cot^2\theta } \]
\[\csc^2\theta-1=\cot^2\theta \]

Answer 2

first one

Answer 3

That's it? And how do you know?

Answer 4

actually its a fact u can put values of x to verify it
sin^2X + cos^2X = 1

L.H.S

=sin^2X + cos^2X

=sinXsinX+cosXcosX

=cos(X-X)

=cos0

=1

Answer 5

i hope its clear ??