arrow
arrow
arrow
If sin(3x - 20)o)^o)o = cos (20 - 3y)o)^o)o, then value of x - y will be :​
Question

If sin(3x - 20)o)^o = cos (20 - 3y)o)^o, then value of x - y will be :​

A.

20o20^o​​

B.

60o60^o​​

C.

30o30^o​​

D.

45o45^o​​

Correct option is C

Given: 

We are given the equation:

sin(3x20)=cos(203y)\sin(3x - 20^\circ) = \cos(20^\circ - 3y)​​

Concept Used:

cos(θ)=sin(90θ)\cos(\theta) = \sin(90^\circ - \theta)  

Solution:

Applying the identity to the right-hand side:

cos(203y)=sin(90(203y))=sin(70+3y)\cos(20^\circ - 3y) = \sin(90^\circ - (20^\circ - 3y)) = \sin(70^\circ + 3y) 

Now,

sin(3x20)=sin(70+3y)\sin(3x - 20^\circ) = \sin(70^\circ + 3y)

3x20=70+3y3x - 20^\circ = 70^\circ + 3y 

3x3y=903x - 3y = 90^\circ 

xy=30x - y = 30^\circ 

​Thus, the value of x−yx - yxy is: 3030^\circ​​

180∘180^\circ Therefore, we have two cases to consider:3x−20∘=70∘+3y3x - 20^\circ = 70^\circ + 3y3x20=70+3y 

Free Tests

Free
Must Attempt

CBT-1 Full Mock Test 1

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

RRB NTPC Graduate Level PYP (Held on 5 Jun 2025 S1)

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

CBT-1 General Awareness Section Test 1

languageIcon English
  • pdpQsnIcon40 Questions
  • pdpsheetsIcon30 Marks
  • timerIcon25 Mins
languageIcon English
test-prime-package

Access ‘RRB NTPC’ Mock Tests with

  • 60000+ Mocks and Previous Year Papers
  • Unlimited Re-Attempts
  • Personalised Report Card
  • 500% Refund on Final Selection
  • Largest Community
students-icon
354k+ students have already unlocked exclusive benefits with Test Prime!
Our Plans
Monthsup-arrow