what are the co-ordinates of the origin

is it (0,0) I am just confirming

Ncert maths class 12 relation and function 

Ex 5.3 4 no

• Another method to solve it ? 
  

Class 12 maths ch 3 examples

Examples of chapter 1class 12

(3+root5) (3-root5)

There are 3 consecutive traffic lights which turns green after 36,42 and 72 sec. They all were green at 9:00am. At what time all turn green simultaneously.

𝑑 2𝑦 𝑑𝑥 2 + 1 − 𝑐𝑜𝑡𝑥 𝑑𝑦 𝑑𝑥 − 𝑦 cot 𝑥 = 𝑠𝑖𝑛 2𝑥