Which of the following are true statements I sin2cos21 II se

Which of the following are true statements?

I. sin2+cos2=1

II. sec2+1=tan2

III. 1+csc2=cot2

IV. 1csc2+1sec2=1

I am aware I have to re-learn the identies.

Solution

Given the statements:

I. True for Sin²x + Cos²x =1.

II. False, because Sec²x = 1 + tan²x

III. False, because csc²x = 1 + cot²x

iV. False, because is is different to 1.

Let me know if you have any question.