If \(\cosec x-\cot x=\frac{1}{3}\), what is the value of (\cosec x+\cot x)?
Answer and explanation
Correct answer: 3
Using the identity \(\cosec^2 x-\cot^2 x=1\), we get \((\cosec x-\cot x)(\cosec x+\cot x)=1\). Given \(\cosec x-\cot x=\frac{1}{3}\), so \(\frac{1}{3}(\cosec x+\cot x)=1\). Therefore, \(\cosec x+\cot x=3\). The value \(\frac{1}{3}\) is the given expression; its reciprocal gives 3. Exam tip: recognise \(\cosec^2 x-\cot^2 x=1\) and multiply the conjugate expressions in such questions.
Frequently asked questions
What is the correct answer to this question?
3
Why is this the correct answer?
Using the identity \(\cosec^2 x-\cot^2 x=1\), we get \((\cosec x-\cot x)(\cosec x+\cot x)=1\). Given \(\cosec x-\cot x=\frac{1}{3}\), so \(\frac{1}{3}(\cosec x+\cot x)=1\). Therefore, \(\cosec x+\cot x=3\). The value \(\frac{1}{3}\) is the given expression; its reciprocal gives 3. Exam tip: recognise \(\cosec^2 x-\cot^2 x=1\) and multiply the conjugate expressions in such questions.
Which subject and chapter does this question cover?
This is a Class 12 Mathematics question. Chapter: Trigonometric Functions. Topic: Trigonometric functions and their properties.
