What is \(\frac{\sin 2x}{1+\cos 2x}\) equal to?
Answer and explanation
Correct answer: \(\tan x\)
Use the double-angle identities \(\sin 2x=2\sin x\cos x\) and \(1+\cos 2x=2\cos^2x\). Therefore, \(\frac{\sin 2x}{1+\cos 2x}=\frac{2\sin x\cos x}{2\cos^2x}=\frac{\sin x}{\cos x}=\tan x\). \(\cot x\) is the reciprocal of \(\tan x\), so it is not correct. Exam tip: first substitute the double-angle identities before cancelling common factors.
Frequently asked questions
What is the correct answer to this question?
\(\tan x\)
Why is this the correct answer?
Use the double-angle identities \(\sin 2x=2\sin x\cos x\) and \(1+\cos 2x=2\cos^2x\). Therefore, \(\frac{\sin 2x}{1+\cos 2x}=\frac{2\sin x\cos x}{2\cos^2x}=\frac{\sin x}{\cos x}=\tan x\). \(\cot x\) is the reciprocal of \(\tan x\), so it is not correct. Exam tip: first substitute the double-angle identities before cancelling common factors.
Which subject and chapter does this question cover?
This is a Class 12 Mathematics question. Chapter: Trigonometric Functions. Topic: Trigonometric functions and their properties.
