Question

Which expression is not equal to 1?

sin θ csc θ
cos θ sec θ
tan θ cot θ
sin θ cos θ

Answer 1

sin θcos θ

hope it is helpful to you

Answer 2

sin A cos A

Explanation:

[ I don't know to type angle theta here so assume A as theta]

As , sin A= p/ h

cos A= b/ h

so,

sinA cosA = p/ h × b/h

= pb/ h^2 ( which is not equal to 1 )

Tip; you can easily verify other relations expressing trigonometric ratios in terms of p,b & h and further simplifying..