Start learning →

Which of the following is true?

A$\tan 90^\circ=1$
B$\sec 90^\circ=1$
C$\cot 90^\circ=0$
D$\csc 0^\circ=0$
Answer & Solution
Correct answer: C. $\cot 90^\circ=0$
From the standard trigonometric values, $\sin 90^\circ=1$ and $\cos 90^\circ=0$. So $\cot 90^\circ=\frac{\cos 90^\circ}{\sin 90^\circ}=\frac{0}{1}=0$. The others are false because $\tan 90^\circ$ and $\sec 90^\circ$ are not defined, and $\csc 0^\circ$ is also not defined.
Practise this question with Quill — CBSE Class 10 →
Related questions