arrow
arrow
arrow
Simplify: 1−sec⁡xcosec⁡x⋅cot⁡x\frac{1 - \sec x}{\cosec x \cdot \cot x}cosecx⋅cotx1−secx​​
Question

Simplify:
1−sec⁡xcosec⁡x⋅cot⁡x\frac{1 - \sec x}{\cosec x \cdot \cot x}​

A.

​(cos⁡x+1)cot⁡2x (\cos x +1) \cot^2 x​

B.

​(cos⁡x+1)tan⁡2x (\cos x + 1) \tan^2 x​

C.

​(cos⁡x−1)tan⁡2x (\cos x - 1) \tan^2 x​

D.

​(cos⁡x−1)cot⁡2x (\cos x - 1) \cot^2 x​

Correct option is C

Given
Expression = 1−sec⁡xcosec⁡x⋅cot⁡x\frac{1 - \sec x}{\cosec x \cdot \cot x}​​

Formula Used
​sec⁡x=1cos⁡x csc⁡x=1sin⁡x cot⁡x=cos⁡xsin⁡x tan⁡x=sin⁡xcos⁡x \sec x = \frac{1}{\cos x} \\\ \\\csc x = \frac{1}{\sin x} \\\ \\\cot x = \frac{\cos x}{\sin x} \\\ \\\tan x = \frac{\sin x}{\cos x} \\\ \\​​

Solution
Convert all trigonometric terms into sine and cosine.
Numerator = 1−sec⁡x=1−1cos⁡x=cos⁡x−1cos⁡x 1 - \sec x = 1 - \frac{1}{\cos x} = \frac{\cos x - 1}{\cos x}​​
Denominator = csc⁡x⋅cot⁡x=1sin⁡x⋅cos⁡xsin⁡x=cos⁡xsin⁡2x\csc x \cdot \cot x = \frac{1}{\sin x} \cdot \frac{\cos x}{\sin x} = \frac{\cos x}{\sin^2 x}​​

Expression = cos⁡x−1cos⁡xcos⁡xsin⁡2x \frac{\frac{\cos x - 1}{\cos x}}{\frac{\cos x}{\sin^2 x}}​​

Expression = cos⁡x−1cos⁡x⋅sin⁡2xcos⁡x\frac{\cos x - 1}{\cos x} \cdot \frac{\sin^2 x}{\cos x}​​

Expression = (cos⁡x−1)⋅sin⁡2xcos⁡2x(\cos x - 1) \cdot \frac{\sin^2 x}{\cos^2 x}​​

Since sin⁡2xcos⁡2x=tan⁡2x: \frac{\sin^2 x}{\cos^2 x} = \tan^2 x:​​

Expression =(cos⁡x−1)tan⁡2x (\cos x - 1) \tan^2 x​​
Final Answer
So the correct answer is (c)

Free Tests

Free
Must Attempt

RRB NTPC UG Level PYP (Held on 7 Aug 2025 S1)

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
Free
Must Attempt

CBT-1 Full Mock Test 1

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
Free
Must Attempt

RRB Group D Full Mock Test 1

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
test-prime-package

Access ‘RRB Group D’ Mock Tests with

  • 60000+ Mocks and Previous Year Papers
  • Unlimited Re-Attempts
  • Personalised Report Card
  • 500% Refund on Final Selection
  • Largest Community
students-icon
564k+ students have already unlocked exclusive benefits with Test Prime!
Our Plans
Monthsup-arrow